agrnrmunn—
112: 245
Univ.-Hibl. Giessen

18.

Te LA TT 1-S P
(OE N
PP LOUVC WS
aN D
WHEEL CARRIAGES,
OU SDRATED BY PLATES,
BL JAMES SMALL PrLoucH xp C4rT WricEr,
formerly at Blackadder-mount, now at Roſe-bank, near
Foord, Mid Lothian, EE+0
IT boldly recommend a plough introduced int DES Scotland about twelve years A400, by JAMES SMALL a Blackadder-mount, Berwickſhire, which is now in great requeſt. This plough may be conſidered as 2 capital im- ÞProvement.
ECDL
Printed for the AuTnoR, and ſold by W. CREÈ
€. Er.1.IoT, Edinburgh, and T. CADPEL, London, fh M.DCC.LXXXIV. e C/

(4

TO
ALGAS ANDER REN FON
OF LAMERTON, ESQ;
MOST HUMBLY awp RESPECTFULLY INSCRIBED, AS À TESTIMONY OF RESPECT AND GRATITUDE
FOR THA COUNTENANCE AND PROTECTION SO LONG AFFORDED DB IS
MUCH OBLIGED SERVANT

0

C ON FEND S
Tnutroduction-- Page I Of the action of a plough in general IL Of the coulter-- IS Of the ſole and ſock of the feather ſock plougb 5x Of the mouldboard-- 37 Directions for making ſock maundrels I 40 Directions for framing the plough 1bid, Of the uſe of a chain on the plough 149 Of the uſe of wheels 10 a plouch I52 Of turning the furraw to either ſide at dleaſure-= 178 Of wheels in general-_ I99 Of the diſh or cavity of wheels- 202 Of rhe length of the naves- 270 Of the raper of the buſhes“ 2E
Of firting in the buſhes“>18

E. ON
Of the ſole of a wheel- Page 22.1 Of fitting in the axles- 222 Of finding the diſh of the whec!- 225 I. By a ſquare and ruler- 226 2. By calculation— RE y Tó find the length of the axle bed 229
Of the gathering of the wheels forward 240 Of the manner of placing, the carriage on
the wheels-- 244 Of fixing the axle on the carriage- 246 Some remarks on the obſervations made
by Mr Jacob on the bending of the
axle-arms downward
D A O
INTRO-
“zii as,

INTRODUCTION.
THE Plough is an inſtrument of ſuch importance in agriculture, that, in all ages, it has held the firſt
place among the implements of that
art; nor is there any nation mentioned
in hiſtory, who have attempted to cul- tivate the ground without it, except- ing ſome Barbarians, deſtitute of every art and ſcience. And even theſe have uſed ſomething eguivalent, ſome turn- ing up the ground wich the horns of oxen, and ſome with other things equal- Iy unfit. Theſe rude and barbarous at- tempts only ſhow the great uſefulneſs of the inſtrument of which I propoſe
to treat. A Though

1 INTRODUCTION
Though many of the ancient nations underſtood agriculture very well, and had invented ploughs of different forms, all of them ſcem to be inferior to ſome of thoſe lately introduced among Us. Although the ancients had made great Progreſs in the arts of life, their know- ledge of mechanics was more imper- fe, and leſs diffuſed, than among us, and therefore their Improvements will not bear a compariſon with thoſe which have taken place within theſe two laſt centuries.
ït is ſomewhat ſtrange, that, amidſt all the improvements which have been made during this period, the plough ſhould have remained almoſt în the ſame ſtate, till within theſe laſt fifty years, The truth is, that it has been
neglected
ep— <

IN E RODUVCT- TONE 5% neglected by thoſe perſons who have turned their attention to machines, as 2 rude tool, unworthy of their atten- tion. Such perſons imagined that any ching could do for the clumſy operation of turning up the ground, and that there could be no nicety in a work which was ſucceßsfully performed by the ignorant peaſants. Other perſons have imagined, that it is impoſlible to explain the principles by which. the plough performs its work. If this be true, we muſt ad at random in making this important inſtrument, without knowing whether we are right: or wrong, except by the event; and if che plough ſhould not anſwer our pur- poſe, our attempts to amend it muſt be without rule; andas liable to error as
Deore, Dotz

x INTRODUCTION:
Both theſe opinions are very errone- ous, and the maintaining them would be produdive of very bad conſequen- ces, by: checking the improvement of agriculture: For, although our know- ledge of the nature of plants, and of the manner of promoting their growth, ſhould improve ever ſo much, and the huſbandman ſhould know, that, if his ground were ſo and fſo dreſſed, his crops would be improved, yet, if the imperfedtion of the plough be ſo great, that this dreſſing cannot be given with- out a very great expence, the know- ledge of the huſbandman is rendered almoſt uſeleſs,
The plough is ſo far from being a rude and deſpiſable tool, that it is a machine aof very ingenious contrivance, even in
the
1

i Pj
1
INERODICIIO N wy
che rudeſt form in which it appears in
this country. Several circumſtances in the conſtruction, even of our oldeſt ploughs, are far from being obvious, and yct the negle& of them would have rendered the ploughs much leſs fit for their work than they are, The circum- ſtances, upon which the goodneſs of a plough depends, are both many, and difficult to be diſcavered; and it re- quires bath great ingenuity and great experience to determine that form of a plough which will enable it to perform its work in the beſt manner, and with the leaſt labour poſſible. So that, whe- ther we conſider the importance of the plough, or the great nicety of its con- ſtrudion, ît is a ſubje(t very fit for ex- erciſing the genius of the moſt eminent
mechanics

vi IN FRODUCATION., mechanics and philoſophers in Europe, On the other hand, this is not a taſk which exceeds the powers of our un- derſtanding; and it is not impoſlible to explain the principles upon which the plough fads in performing its work: and, conſequently, to determine that form which ſhall do this in the beſt manner. Let the huſbandmen once be agreed as to the fate în which the ground ſhould be Ieft by the plough, The taſk which it is to perform is now a fixed ching, and there muſt be one manner of performing ît, which is bet- ter than any other. Now, it is certain that a plough may be made which ſhall perform a taſk in any manner what-
ever, and therefore in this beſt INAN
NET

ENST O DUCTION: as
Ir would be great preſumption in me,
it I ſhould pretend to give perfect in- ſtruction in a ſubje& which I have hid is fit for exerciſing the greateſt genius. My ſituation in life has deprived me of many advantages of theoretical Iearn- Ing.
But, on the other hand, it has given Ine a good deal of experience, both as a huſbandman, and an artificer.‘This advantage appears to me conliderable, and not very common, and has engaged Imc To furn my attention to the improve- ment of the plough more than many 0- thers of my profeſion. Some of my views were much approved of by gen- tlemen of great judgement and CexXperi- ence, which encouraged me to beſtow Ni more attention upon the ſubjed,
and

(ii INTRODUCTION:
and to put immediately in practice€e- very alteration which I thought would be an improvement. Ict is to fuch en- couragements, and the opportunities thereby given me for improving my ploughs, that I ani indebted for the good character which they have given me, both in this neighbourhood and at a diſtance.
The ſame gentlemen who have en- couraged my attempts to improve the plough, have alſo flattered me with the hopes that I would do a ſervice to ſoci- ety, if I ſhould make public my notions upon this ſubje&. I have therefore ſet them forth, ſuch as they are, with ſome degree of truſt that my ſentiments will be found pretty juſt, and with almoſt a certain confidence, that ploughs, made
CS

enl- the 1 the ſoci- tions e ſet ſome ; will oft a made
CNS O DUCT TON. Six according to the dire¿tions which I have given, will be found to perform their work in an agreeable manner. If any perſon of ſkill ſhall think iet worth his while to corre any miſtakes into which I have fallen, he will deſerve well of the Public, and will have my particular thanks for the opportunity which he will thereby give me of im- proving in my profeſſion. The chief merit which I claim in the following ſheets is this, that I have given dire@ions by which any ſenſible workman may De enabled to make a plough on my principles, without being reduced to the neceſlity of copying, and that thoſe di- rections are ſuch as will enable him to make a plough on any principles what- ever. All that is neceſſary to be known
B 18

x I1INTRODCTEON:
is the ſtate in which the ground is to be left by the plough. My directions en- able the workman to make a plough which ſhall leave it in that ſtate. So that, whether my-principles are good or not, my direGions for making a plough loſe nothing of their value.
I hope that a candid and good na- tured Public will receive, with indul- gence, my endeavours to be uſeful, and will pardon thoſe defects which ariſe cither from my ſituation, or from my want of talents. TI am too ſenſible of the reſpeXt which is due to the Public,
to be wanting in care and attention-

1-
Of the Aion of a Plough
in general.
Y N ploughing three things are per-
formed. A ſlice of earth is cut off from the general maßs. This flice 1s removed ſome inches to one fide. It 1s ſo turned, that ic may expoſe a new ſurface to the air, and that what was formerly uppermoſt may now be buri- eds Totthe- pérſormance of- thelé things, the conſtruction of the plough muſt be adapted, and the work muſt be performed with as little labour to the cattle, and to the ploughman, as poſ- ſible; and the ploughman muſt have it in his power to vary at pleaſure the depth, wideth, and poſition of the fur-
OW

T2 Aétion of the plough in geueral.
row. The firſt of theſe adions is per-
formed by the coulter, the ſecond and a- 7 X?
third by the ſock and moüldboard
jointly. Theſe are to be conſidered in
order. Of the Coulter.
The coulter muÊft be conſidered as a cutting inſtrument, oppoſed to great and varions refiſtances. It muſt be ſharp, that it may cut the more eaûly, and ſtrong, that it may not be broken or bent. Theſe properties cannot be unic- ed, unleſs it is thin and broad. The giving it great ſtrength, by means of great thickneſs, expoſes it to more re- ſiſtance than is neceſlary; whereas, in- creaſing the breadth of the coulter di- miniſhes the reſiſtance, by making it a
fharper wedge,
The
——>

Of the Coulter. I3 The dimenſions of the coulter may be as follows: An eighth of an inch thickneß at the edge, and an inch thick at the back, for a three horſe plough, or ſeven-cighths for a two horſe plough, The web may be three inches broad at the broadeſt, and taper from a foot down all the way to the point, The thickneſs of the back may taper alſo. The length is about twenty inches. It may e a little rounding on the fur- row fide, from the edge to the middle, and ſhould be flat on the land ſide. The operation of the coulter depends greatly upon its poſition, The plough may be conſidered as a ſort of wedge, employed to remove the earth both from the land ſide and from the bottom of
the furrow. The land ſide and bottom
of

I4 Of the Coulter.
of che furrow, are, cach of them, to be kept ſtraight. This circumſtance, as we ſhall ſce more fully afterwards, re- quire that the land ſide and ſole of the plough be plane ſurfaces. The coul- cer therefore muſt be placed in the plane of the land ſide of the plough. By this means, the cut which it makes forms the land ſide of the furrow, to which the plough is afterwards preſled, by the reſiſtance ating upon the fur- row ſide of the ſock and mouldboard. For the ſame reaſon, it appears proper to me, that the land fide of the coulter ſhould be in the plane of the land ſide of the plough, and that its whole thickneſs (houid be on the furrow fide. When the plane of the coulter has any other poſition, there will always be a force
acting

Of the Coulter. E57 acing on the plough, tending to change its direction. This mult be op- poſed by the continual influence of the pioughman, or by the form of ſome c- ther part of the plough, which fhall give it a contrary tendency. The firſt method is evidently improper. The ſe- cond is no leſ? ſo, becauſe, though theſe contrary tendencies may balance each other, they both increaſe the la- bour of the cattle. It may be objeâted to this reaſoning, that by making the land ſide of the coulter in the ſame plane with the land ſide of the plough, or parallel to it, the coulter itſelf will be preſſed in towards the land, by the reſiſtance of îts furrow fide. This is true, but 1s, in. general, compenſated by the firmneſs of the ground on the
land

ió Of the Coulter. land ſide. When the edge of the coul th ter ſtrikes a ſtone direAly, the ſtone, al- Fc though driven ſtraight forward, moves| BV to the furrow ſide, where it is leaſt re-| ſiſted. But if the coulter has its edge fi exaly in the middle of its thickneſs, i| and ſtrikes a ſone with its land ſide, I the plough muſt be thrown from the| e land, becauſe the ſtone cannot be preſ 100| |
ſed much farther into the firm ground.|M
In fitting the coulter into the beam,|W| the mortiſe muſt be made parallel to the| Fo)* plane in which the plough moves, and: M niot pointing to the furrow ſide, as is thn| much practiſed; for this practice al- W| ways gives the plough a tendency to M turn off from the land. The poſition N which I here recommend for the edge LL of the coulter, cauſes it to co-operate Fi
with (

Of the Coulter 7 wich the[gélé and mould-board, in re- moving the earth, which 1s an advan- tage not to be delpiied.
The loſs ſuſlained by the wrong po- ſition of the coulter, does not very ſen- fibly appear in a plough which is drawn by the beam, projecting ſo much before it: but would be very diſtinWly fele, if the draft chain were faſtened to the coulter itſelf. In this caſe, it would be found that it will be hardly poſſible to keep it in its proper diredtion-
Another thing to be taken notice of with reſped to the poſition of the coul-
+ ter; is its rake, or inclination forwards. It would ſeem, at firſt fight, that the edge of the coulter ſhould be upright; but experience, perhaps without any principle, has directed us to point ic
C forward

x6 Of the Coulter,
forward below. Some principles are, in this caſe, perfeâly conformable to cx- perience. In the firſt place, the Încli. nation of the coulter makes it cut the earth more eaſily; for, it is well known, that, in all operations wich eutting in- ſtruments, the work is more eaflily per- formed when the edge of the inſtrument is placed oblique to the direQion of its motion. I cannot give a better in- tance, than the operation of ſhaving, where the refiſtances in the different
poſitions of the edge of the raſor are
moſt eaſily diſtinguiſhed. Some think,.
that a lof is ſuſtained by the point of
the coulter cutting the furrow o much below, before it is cut above. Buc it may be ealily ſhown to ſuch perſons, that no loſs is ſuſtained; but, on the contrary,
A
——_—_——
YN!
N)

0
/3
Of the Coulter.[9 a real advantage is gained. When the point of the coulter projets much be- low, it cuts the ground partly upwards, in which direétion îts coheſion is moſt eaſily overcome. Alſo, when the coul- ter comes to tough roots, which it docs not cute at the firſt touch, it preſſes for- ward below them, fMrains, and tears them with the increaſed force of a wedge, and at laſt breaks them, with much greater eaſe than if its edge were upright. By this means too
a very tough root is made to ſlide up
along the coulter, till it comes to that
part of its edge, which is not much em- ployed in cutting the farrow, and is therefore ſharper than the reſt. E the roots being cut by different parts of
the coulter, as they differ in ſtrength,
and

20 Of the Coulter» and being, in general, thrown up to its top, the coulter is cleared of them in that part chiefly employed in cutting the furrow- A
But if the edge of the coulter were perpendicular, it would carry along with it the roots which it does not cut, which would greatly increaſe the refiſ- tance which it meets with, and would frequently choke the plough, and ſtop its motion. In like manner, when the coulter comes to a ſtone, it makes it riſe upwards, in which direion it is more eaſily moved; whereas, if the edge were perpendicular, it behaved ta force it ſtraight forward.
Another advantage attending this in- clination of the coulter, is, that it tends to keep the plough in the ground,
That

its
Of the Coulter. 2E
That ſome force is neceflary fax this purpoſe will eaſily appear. In the man- ner in which cattle are commonly yoked, the line of draught makes an angle of about 24 degrees with the ſole of the plough, or bottom of the tur- row,‘The tendency of the draught therefore, is always to pull the plougl out ofthe ground; and if the edge of the coulter were upright, it would give no oppoſition to this tendency, Nay, even if the coulter were pointed 24 de- grees forward, it would not have any efe, It muſt therefore projet fll more, in order that the reſiſtance upon. its upper edge may co-operate with the reſt of the plough, in oppoſing this ge- neral effed of the aſcent of the line of draught, This additional projection of

52 Of the Coulter.
óf the coulter is the more neceſlary, for the purpoſe of keeping the plough in the ground; becauſe, as we(hall ſce afterwards, there are other circumſtan- ees which alſo tend to throw the plougli out of the ground.
I would therefore teconimehd an in- clination, or rake, of abouc 45 degrees, as the moſt proper, and the moſt cóôn- ducive, to all the good purpoſes hither- to mentioned.‘The propriety of this poſition will be illuſtrated by conſider- ing figure ift. Let A H repreſent the fine of draught, making an an gle of 24 degrees, with L M, the bottom of the furrow. This line of draught is ſup- poſed to paſs through the centre of efftort of the plough. Let it cuc the
‘édge of the coulter in N. This point
w11}

es, on- El- chis
ler-
the
Of the Coulter. 22 will be found to be about 4 or 5 inches from the bottom of the furrow, though N draw C D perpendicular to A H I. Then, if the edge E F of the coulter makes an angle of about 45 degree: witt L M, ic will make an angle of a- bout 20 degrees with C D. There bez ing nearly the ſame quantity of earth cut by the part below N, as there is cut by the part above N, the coulter will be equally preſſed on each ſide of the line of draught, and will, in this re- ſpect, have no tendency to turn the plough out of the ground, nor into it. This poſition will therefore be the molt Proper, when the ſock is at the longeſt, and will admit of being changed, ſo as to bring the point of the coulter near (o the ſock; when this is ſhorter, while
the

ÍA Of the Coulter
the ſock is of ſuch a length as to maké the coulter more inclined than C D, the coulter will always help to keep tlie plough in the ground.
The next thing to be conſidered in the poſition of the ¿itch reſpects its fitneßs for clearing, or freeing, the part of flie, plough which follows it in the fuürrow.|
The defeQs of the common form of the land ſide of the plough, and of the poſition of the coulter correſponding to it, are very ſenſible, both when we uſe the long praiſed ſpear ſock, and plain mouldboard; and alſo when we uſe the more modern feathered ſock, and curved mouldboard. Theſe defedts have bed diſtin@ly ſcen by the aQual compariſon with a plough of a. more
PCr-
/ x Vi dl ip(1
Hr

mak
) tlie
ed 1 ets 1tS € Pat
n the
rm of oí he ling to WVC ule ) plain Ve ule , and defects aQual
1, more
per
Of the Coulter. 25 perfect conſtruction, and may be ſuf- ficiently underſtood, by attending to the deſcription which will now be given of this improved plough.
The ploughi, às has been alécady ob- ſérved, may bé conſidered partly as a cutting inſtrument, of wliich the coul- tér forms the edge. Tc is not employed in cutting the earth, and ſeparating ic on both ſides, in which caſe it would rather reſemble a cleaving inſtrument; but it is employed in cutting a ſmall ſlice from the firm ground, on the left hand, and removing, it to a certain diſ- tance to the right hand, Te cluet Te= liſtance being therefore exerted on the
furrow fide of the plough, the plough
1s preſled to the firm ground on the lefc
hand. By this means the land ſide of
D the

26 Of the Coulter.
the plough becomes the director of its motion, and therefore, in the perfect ſtate of the inſtrument, ſhould perform no other part of the work. This con- ſideration ſhows at once that the land ſide of a plough ſhould be a flat or plane ſurface. If it has any other form, being, ſtrongly preſſed to the firn- ground, ts proje¿(ng; parts muſt ſink into it, and the plough cannot advance without continually tearing of the earth with îts projeding parts; which earth muít tumble in between the coulter and ſheath, or into any hollow in the land ſide of the plough, and, colle&ing gra- dually there, will both obſtruct its mo- tion, and turn it from the land. Here, without any farther argument, appears the great“ imperfe@ion of the Scotch.
plough

Of the Coulter. 24 piough, as uſually made; and the ad- vantage which mußt attend the cover- ing the hollow between the head, ſheath, aud ftilt, with boards, to reduce it to a flat ſurface.
In the next place, this flat ſurface, which forms the land ſide of the plough, muſt be in the dire&ion of the plough's motion; that is to fay, a ſtraight line, drawn from the heel of the plough to the point to which the cattle are yoked, muſt touch the land ſide of the plough. If the ſurface of the land ſide of the plough, and the edge of the coulter, points to the right hand of the fore end of the beam, the plough will be thrown continually from the land; by the reſi tance which it meets with on that ſide, the contrary efe will be produced if
this

28 Of the Coulter. this ſurface points to the left of the fore end of the beam: but when the land fide of the: plough,‘and the line. of draught are in the ſame plane, the plough will go ſmoothly and ſteadily, without any effort of the ploughman. This conſideration leads us to attend a little to the form of the beam. The mortiſe, for receiving the coulter, muſt be in the middle of the thickneſs of the beam, in. order to, aive.the„graateſt ſtrength. The ſame may be ſaid of the mortiſe in the ſtilt for receiving the beam. The coulter muſt be ſet tothe left of the land ſide of the plough, near- Iy the thickneſs of its back, by which means the earth, which is puſhed a little to the right hand by the thickneß of the coulter, will be received on the edge
of

Of the Coulter, 29 of the ſheath and mould-board. Theſe conditions- cannot be obtained, if the beam is equally tapered on the land and furrow ſides, as is uſually praiſed. For, in this caſe, the coulter will have its UpPer Part rémoved to the right hand of the land ſide of the plough by half the thickneſs of the beam. This is ac- cordingly the caſe inthe uſual conſtruc- tion of the plough; and this defed is attempted to be remedied, by placing the plane of the coulter, not upright, but pointing with its lower end to the land, and projeâting beyond the land ſide of the plough near five inches, as in fig. 3, 4, and 9. which repreſent a crols ſection of the plough at the heel, ſeen from the point of the beam. I ſhall firſt deſcribe the conſtrudion,
which

30 Of the Coulter,
which appears to me to be the moſt proper, and then ſhow its advantages, by comparing it with the common form,
The beam ſhould be 4} or 43 thick between the coulter-hole, and the hin- dermoſt ſide of the ſheath, and ît ſhould be 47 or 5 deep at the ſame place. At the fore end, the thickneſs ſhould be 27x» and the depth 32. It may have a curve of 6 inches up and down, which the ploughmen call the redde of the plough.
Inſtead of tapering the beam equally atr both ſides from the place of the coul- ter, as repreſented in fig. 2. No. 2. I make the beam ſtraight on the furrow- ſide, as in fig. 2. No. 1, and taper it only on the land ſide, both ways from the place of the coulter. The taper
backwards

rds
Of the Coulter. 37 backwards to the hindermoſt ſide of the ſheath, ſhould be ſuch, that, when a ruler is laid to tlie ſide in that place, it will projet 2+ inches to the left of the fore end ofthe beam. A B in this figure is the plane óf the land ſide of the plough, which, by this way of ta- pering, paſtes very near the middle of the thickeſt part of the beam. By this method, the coulter-mortiſe is brought over to the land ſide, half of the taper given to the beam. But as this is not fuflicient for bringing the coulter into the poſition formerly recommended, LI give the coulter a knee, or ſet of 2 inch- es, as repreſented in fig. 5, Thus, the coulter may be ſet ſo as to make it cut in the beſt manner, and yet be in the middle of the beam, The ſheath is alſo
nortiſed

22 Of the Coulter.
mortiſed nearly into the middle of the beam, but has a ſhoulder to the land ſide of È an inch. This makes the land fide of the ſheath juſt touch the line A B (fig. 2. No. i.) drawn from the land ſide of the fore end of tlie beam to the land ſide of its other end, and thus the land ſides of the fore end of the beam, of the ſheath, and of the ſtilt, are all in one plane ſurface. This cauſes the coul- ter to clear completely the part of the plough which follows it in the furrow. But when the beam is made in the uſual manner, as in fig. 2. No. 2. the coul- ter does not clear the plough in all the Parts of the land ſide. For, in this caſe, te ne ORE 1) WIr Corelent the land ſide of the ſheath, mortiſed into the middle of the beam, and NK will repre-
ſent

f tlie land land AB land o the 5 the eam, lin coul f he ‘rOW. uſual coul- Il the ; cale, 1t the to the repre-
ſent
OCE Giner. 32 ſent thie land ſide ofthe ſtile,(the point Niof fio 4. correſponding ¿witlt:V-in fig. 2. No. 2.) and the angle OK N will be the twiſt of the land ſide of the plough,(the ſpace ON being about rf inches,) by which it appears, that the land fide of this plough will point to the right of the fore end of the beam, which will give the plough a tendency to guit the land, or to turn into the furrow- In this conſtruction, the coulter, being put ſlanting into the beam, ſo as to pro- ject to the land ſide about 5 inches be- low, does not clear the plough egually in all its parts. For the plane of the coulter interſects the plane of the ſheath about 22 inches below the- beam, and the plane of the ftilc much lower. By 11s means, although the lower part of
E the

24 Of the Coulter.
the plough is more than ſufficientiy cleared, the upper part is not cleared: at all Accordingly, it may be oblſer- ved, that in ploughs- of this conſtruction, the upper part of the plateing on the land ſide is more worn away than the lower, although it moves in looſer earth. Ec is ſtrongly preſſed to: the firm land, while the parts near the ſole do not
touch it, or touch it after the upper
parts have been bruiſed together.
All theſe circumſtances conſidered to- gether, ſhow that a plough of this con- ſtrudion is in a ſtate of continual twiſt- ing, by the very unequal preſſure of its different partsto the land. This muſt be varied by changing the poſition of the coulter, ſo as to point its lower end more or leſs to the land; whereas, by
making

Of the Coulter, 2s näáking the land ſide of the plough in ¿he direcion of its motion, it is kept€-
qually prefiled in all its parts, and there-
fore ſinks Teſs in any one part, which „makes it more ſteady in its motion, and more eaſily drawn, and the coulter, be- ing kneed and placed as direéted, frees the plough completely and equally in
all its parts.
This may‘be further illuſtrated by
fig. 6. which is adapted to a plough
conſtruéted as in fig. 4.
MN is a line drawn through the
very point of the coulter, and hinder-
moſt end of the land ſide. HP isa
Une drawn through the edge of the
coulter, and hindermoſt end of the Tand ſide, one foot up from the ſole, and NR is the line which is paralleŸ
T@®

26 Of thé Coulter.
to the dire@ion of the plough’s motion at a medium. The other two, HP and MN, are nearly equidiſtant on each ſide
of NR. Now, although this is the line
which ought to be in the direétion of
the plough’s motion at all times, it can- not be ſo in this conſtruction, except at one particular depth, becauſe, with eve- ry different depth of furrow, the plough makes different degrees of land, on ac- count of the coulter projeéing oblique- Iy to the land fide.
Theſe defects of the common con- ſtruction are ſometimes not obſerved, on account of other defects of the in- ſtrument, and they are thought to be compenſated by the greater quantity of work which the plough /¿ems to per- form, by having the coulter turned ſo
much

ion and lide
line
Of ile Coulter. ZF much to the land. But this is a deceit, and the quantity of real work is not in- creaſed by this poſition of the coulter. For, by the point of the coulter‘being ſo: much:to the land: ſide! of the ſock, a good part of the flice cut by the coul- ter is not raiſed by the ſock, but broken on the corner of the ſock and ſheath, and,- falling in between the coulter and ſock, obftructs the motion of the plough, and even throws it out of the ground. This obſtruction is moſt diſtin@ly perceived in the plough with a feathered ſock. The furrow ftrikes on the land ſide of the ſock, at its firſt riſe, when it would, at any rate,’ preſs moſt upon what is below it. Alſo, by this preſſing on the land ſide, both of the ſpear and feather ſock, it tends to
turn

AS) Of the Coulter.
turn them to the furrow, and thus the ploughis expoſedto two contrary ſtrains, the coulcer turning it to the land, and the ſock turning it to the furrow. Al- though theſe ſtrains may be made to balance each other, they cauſe an ad- ditional reſiſtance to the plough, and labour to the cattle. Alſo, when the ſpace between the points of the coulterc and ſock is conſiderable, no roots which are between them can bc cut by the fea- ther, but they muſt be torn by the clod, or left behind. There is alſo a piece of the ground, at the corner of each furrow-ſlice, which, not being cut, is broken of, and not raiſed up, and this is the corner, which it is moſt neceílary to raiſe, being the new ſoil. It fre-
guently happens too, that, by not cut-
LN e «
—

Of the Coulter.$9 ting this part of the ground, the fur- row is not raiſed at all, nor turned over, but lefc jumbled in confuſion. And, Zafſtiy, this poſition of the coulter and land ſide is very unfit for regula- äng the motion of the plough. When ehe ſoil 1s ploughed deep, this is not ſo diſtin&ly perceived, by reaſon of the looſe earth which tumbles in between the coulter and ſock, and ſerves to fill up the vacancy between the corner of the ſole and the firm ground, But, in ploughing a ſhallow ſoil, it is very evident. The only parts of the plough which pref on the firm ground, are the coulter, and hindermoſt part of the tand ſide; and the ſmalleßt reſiſtance on
the furrow ſide of the coulter is ſuffici-
ent to turn it to the land.
AIL

40 Of the Coultérè All theſe inconveniencies ſeem to be removed in the conſtruction here re-
comimended.* The point- of-the cou!-
in half an iSch-or an inch of the plane of the ſole, and the edge, with* the land ſide, projects about half an inch or an inch beyond the land fide
of the plough; ſo that the coulter is
about as much beyond the plane of
the land ſide, as the point of the ſock is below the plane of the ſole.
THis conſtru®ion was not relifhed by ſome perſons who had been accuf- tomed to the common form; but, when tried, appeared as much preferable as T have deſcribed it. Tn this conftruc-
tion, the advancing of the coulter ſo far
before

liſhed iccut-
when
Of the Coultér. 4 before the ſock, cauſes it to cut the fur- row ſo much the more forward, before it 1s raiſed by the back of the ſock; but, by the great inclination of the coulter, the furrow is not ſo much cut above when it begins to riſe on the ſock, as its for- ward poſition would make one expe. The furrow is therefore ſooneſt cut in the very place wliere ît is to be ſooneſt raiſed. If the coulter were placed as much behind the ſock as it is here ad- vanced before it; the ground would be raiſed before it is cut, which would in- creaſe the labour of the cattle, by cauſ- ing a ſhorter, or more ſudden turn of the furrow. But here, the furrow be- ing cut at ſome diſtance before the ock, is more eaſily turned, or twiſted
by ic. PF Ic

#2 Of the Coulteh
It has been ſaid, that the coulter thus far advanced’ before the ſock, is more apt to-ſtrike on a ſtone, without hav- ing any ſupport from the ſock, which, in this caſe, receives no part of the ſhock, and then: the coulter 1s more li- able to be bent out of its poſition. But, in compenſation of this, it may bè ob- ſerved, that although the coulter is thus more liable to-be bent, it does not tend’ ſo much to break the plough, which will endure more ſtrain from a ſtroke’on the coulter than from a ſtroke on the ſock. Beſides, when the coulter is no more advanced than: the ſock, and placed at the uſual diſtance on the land fide, it is
as liable to be'hit by a ſtone, as in’ the
conſtruction. now recommended, and:
has no ſupport from the ſock, and the
ſock

a Wil n the ſock.
more
ed at
Of te Coulter. 42 Tock may, at the ſame time, receive a fhock from the ſame, or another ſtone. The chance of theſe ſhocks is therefore double; and if the ſtone is ſtruck by both at once, ît is not turned alide, as it would be if ſtruck only by onc of them, but muſt be carried forward be- fore the plough, through the firm ground. For all theſe reaſons, the con- ſtruction is fill preferable; but, as the
coulter is liable to theſe ſhocks, I have
ſtrengthened it by a ſtay of iron, repre-
ſented by HF, fig. 1. This is on the land ſide of the coulter, and turns on 2 bolt through the coulter at F, and paſles through the cye of a bolt I, which paſ: íes through the beam. The upper part, H I of the ſtay is ſcrewed, and the nur which turns on it ſupports the ſtay, and
lle

44 Of the Coulter.
enables us to raiſe or lower the coulter at picaſure. This ftay alſo produces another good effet, by preventing the ſtubble from being preſſed up into the angle formed by the coulter and beam, from which it is very troubleſome to diſlodge it. I may here obſerve, that it is not a good pradice for the plough- man to puſh the ſtubble which gathers on the plough to the furrow ſide. It ſhould be puſhed to the land fide, ſo that it would fall into the track of the
plough, and be buried; whereas, by
puſhing it to the furrow ſide, ic is apt
to lye above. It is alſo eaſier for the ploughman, with his right hand, to puſh it to the land ſide.
On the whole, this poſition of the coulter, a little to the left of! the Tand
ſide

lter luces » the o the eam, ne to hat it ugh ithers 6:16 \e,(0 of the as, Dy 1s apt or the
nd, to
of the
e land
ſide
Of ihe Coulter. 45 Gdeueß the plough, and parallel to it, cauſes the coulter, by its thickneſs be- hind, to bring the furrow exactly on the edge of the ſheath and mouldboard. No earth falls in between the plough and firm land in wet or looſe ſolls; none ſtrikes on the edge of the ſheath and mouldboard in hard ſoils, but the furrow ſlice takes a regular riſe, with its corner right with the land fide of the ſock. No roots can paſs between the coulter 3nd ſock without being cut, and the coqrner is kept in the furrow, and turned up. And, Zafily, the whole land ſide af the plough being equally preſſed to the firm ground, the preſſure on no part is very great, and the plough is prevented from ruaning in- to the firm ground by any ſudden
ſtrain on the oppofite fide.
The

46 Of ihe Coulter.
This conſtruction has alſo been uſed with the coulter Ro farther advanced than the ſock; but in this caſe it has been thought an advantage to place it 2 very little more to the left, but ſill PAa- rallel to the ſide of the plough. But ic has been found, on trial, that it was UII better to advance the coulter be- íore the ſock.
It may be proper here to obſerve, that a plough conſtructed as above di- rected, makes a furrow conſiderably different from that made by a plough of which the lower point of the coulter projects ſo far to the land ſide. This will be illuſtrated by conſidering figures Sand 9. In figure 8. AB repreſents che coulter of figure 5. EK is the ſec- tion of the mouldboard, where it cuts
the

Of the Coulter. 47 ¿he furrow, and K B repreſents the ſole of the plough. EF GH repreſents the ſce cut off from the firm ground, re- moved to the right hand, and turned over. EH is the under ſurface’ of the fce, formerly joined to K B, aúd E is the corner which was formerly at B. This ſlice is made to ſtand upon one corner G, with its former upper ſur- face E G leaning upon the next ſlice. In this figure, the plough is ſuppoſed to be going perpendicular, this being the polition which I would always re- commend. The poſition alſo of the furrow ſlice, which I have here repre=- fented, is that which is approved of by the moſt intelligent farmers. Figure 9 repreſents the ſame thing,” correſpond- ing to a plough made according to fg.
O 4»

48 Of the Coultét« 4. In tlieſe two figures, it appears that the upper and under corners, E G, of the farrow flice, made by the plough, fig. 5. are ſquare, whereas the two cor- ners, R and N of che flice made by the plough of fig. 4. are about 13 degrees above the ſquare. In order‘that the furrow may ſtand in this poſition, ic muſt cicher lean upon the former fur- row, or it muft be ſupported by looſe earth, which tumbles in below it, and fills up the vacancy repreſented by H GK of fg: 8. or PRS fig. 9: Ic is caſy to ſce, that the vacancy of fig. 8. is eaſier made up than the other. Although this poſition of the furrow ſlice is not always required, it-being ſometimes thought proper to leave it ſtanding upon its edge G H, it 1s plain,
that

's that GY of ueh; 0 Cr oy the legrees
at the
m, it
' fur- il, 0d | by H
[c 18
Ye 3, 15
farro t being leave it 5 plait),
that
Of the: Coulter 49 that even in this caſe the plough of fig. 5. has the advantage; for the furrow flice made by it will ſtand upright, whereas that made by the plough Bes 4- will lean to the ſpace left by the plough, and it will hardly be poſlible to prevent it from falling back into its former po- ſition, eſpecially in ploughing wich a ſhallow and broad furrow.
Laſi!y, It appears that the plough of üg. 5. will leave the ploughed ground with a flater toped furrow than the plough of fig. 4. which is alſo thought an advantage by the moſt intelligent farmers.
The reader will obſerve, that I have always ſuppoſed that the land ſide of the plough is kept perpendicular. It is
a very uſual practice to Iean the plough
G Over

5D Of the Coulter.
over to Ue left, or land ſide; but I do not approve of this pracice, becauſe ic leaves the bottom of the furrow higher on the ſurrow ſide, and this leaves ſome of the earth not raiſed, and the furrow turned over has not ſo full a ſhoulder. Tt is in ſome degree to: make'amends for this, that the coulter is ſet ſo far to the land: below. But the practice ſhould: be laid’ aſide, and. then this improper poſition of the coulter will not be neceſſary.
Thus it appears, that whether we conlider the working of the plough, or the work which it performs, the ptough of fig. 5. having its land ſide a plane furface, ſtanding in the direction of the plough’s motion, witli the coulter pa- rallel to ît, is, in every reſpe&, prefer-
able
(dt

ſome rro oulder, mends far to
hould
Of the Coulter. 541 able to the plough fig. 4. which has its fand ſide twiſted, and the point of its
coulter turned ſo far into the land.
Of the Sole and Sock of the Fearber Sock Plough.
In the make of the ſole of this plough, three things are to be confidered.
Firft, The form of the land fide ſole, or head, and the poſition of the ſock, for keeping the plough at the proper depth and breadth of the furrow, and Solid in its motion.
econdiy, The breadth from the out land ſide ſole, to the out ſide of the mouldboard ſole behind, and the incli- nation and height of the mouldboard ‘ole, with reſped to the land fide ſle.
C ¿1 AIE Ig THI di Vo

52 Of the Sole and Sock.
Thirdly, The proper breadth and in- clination of the feather, correſponding to the breadth and inclination of the ſole.
Firſt then, with reſpeätito‘the form of the ſole, and the póſition of the ſock, which are moſt proper for keeping the plough at a proper depth, and ſolid in its MOON. ns 15 A POIIt of the greateſt difficulty in the conſtruction of the plough, and therefore muſt be minutely conſidered. i
Let L M, fig. I. repreſent the bot- tom of the furrow. As the plough advances, its fore parts and furrow ſides are expoſed to refiſtances. The coulter is preſſed down by the earth which it is cutting. The ſock is pref ſed down, and alſo a little to the left
=
by

Nd in. nding
of the
è form. e(ock, ng the olid în { the uCion
nai he
he bot- plougl furrow
The e earth 1s pred che lefr
y
Of the Sole and Sock. 53 by the earth which ic-is raiſing. The fore part of the mouldboard is preſſed down, and alſo to the left by the earth which it is partly raiſing, partly ſhift- ing to the right, and partly turning 0- ver. The hindermoſt part of the mould- board is preſſed to the left by the earth which it is forcing to the right, and is alſo preſled upwards by the earth which it is turning over. Theſe reſiſtances, taken together, give to the plough a tendency to thruſt the point of the irons deeper into the ground, and to twiſt the point of the ſock downwards to the right, and the hindermoſßt part of the mouldboard upwards to the left.
If, therefore, the plough were drawn forward, by a rope faſtened to the point
of the ſock, and level with the bottom of

54A Of the Sole and Sock.
of the furrow, the plough would infal- bly ſink at the point, and riſe at the heel; and, at the ſame time, twiſt o- ver to the furrow ſide. With ſuch 2 draught, therefore, the ploughman muſt continually preſs upon the left ſtile. But the plough is not drawn in the manner here deſcribed, but in an oblique di- rection E A, from the bridle bolt K to the point A, where the draught ropes paſs through the horſes backbangd. This direétion of the draught tends to pull the plough out of the ground, That this may not happen, the draught mult be ſo placed as juſt to balance the plough’s tendency to go deeper. Sup- poſe H A to be the direGion of draught which is exaly proper for this purpoſe. Produce the line A H backwards, till IL
4 NICCL
Pa

Id inf]. at the wilt 9: | ſuch 4 an muſt tilt, But nanne: Jue di- it Kto ropes KONOÓ, ends to round, lraught nce the
SUP- lraught urpoſe, , tilli
7:11 meci
Of the Soîe and Sock. 55 ineet the coulter in N, the ſock in O, and the ſole in I. Every perſon ſkilled in the principles of mechaniſm knows, that the motion of the plough will be che ſame, whether the draught rope is fixed át H, N, O, or I, as the direction TTA is the direction of the draught, ſo A HT is the direcion of the reſiſtance, the labour of the cattle being the ſame as if the plough were not reſiſted by the earth at all, but were kept back by a«rope faſtened at HNO, or I, and pulling; in* the dirééion HE There will, therefore, be‘ ſome point in the Plough, between H and I, where all the reſiſtances may be ſuppoſed to be uni- ted. We ſhall, for the future, call this Point the centre, or point of refiſlance. We may alſo call it the centre of aGion,
be-

56 Of the Sole and Sock becauſe-the action of every part of che plough is directly oppoſed, and is equal to the reſiſtance which that part over- Comes. E ta, If we conſider the preffure on the hindermoft parts' of the mouldboard, which tends to raiſe it up, we fluall find that the plough will not ſwim fair, as the ploughmen expreſs it, but will riſe at the heel. This effect will be fill far- ther increaſed, if the point of the coul- ter or ſock meet with any uncommon obſtacle. In fuch a caſe, if the draught rope is fixed at the centre of action, or any where behind it, the heel of the plough will always riſe, and the plough will twiſt downward on the furrow ſide. But if the draught rope 1s fixed at H, this riſe of the heel will ſtop in time,
be-

tof th 15 equal
UT Oer
on the 1board, lull find fair, as vill riſe Ull far- ne coule cOImNMON draught X10n,- 0! ] of the 017 fide, ed at Y, n time,
be-
D
Of ihe Sole ând Sock ir, becauſe, by this means, the point of the beam is depréſſed, ánd the line of draught comes to make a greater angle with the level of the furrow. When this happens, the draught again raiſes the point of the beam, and ſinks the heel of the plough. It is evident, how- ever, that the motion of a plough trim- med in this manner, will be very hob- bling and irregular:
This defe& is removed by-a very ſim- ple contrivarice; namely, by fixing the draught-rope to ſome point K, below the ſtraight line A T, which paſſes thro? the centre of adion. By this means, the. plough becomes a ſort of lever, of which the centre of aGion is the ful- crum. The lever is pulled upward at K, and, being ſupported at the fulcrum,
H the

(0,0,
Y Of the Sole and Sock.
the lunder part of it is preſſed down, and the heel of the plough M is kept firm in the bottom of the furrow. This
makes the*plouoh go dolid, as the
loughmen expreſs it, ahd neither 0 ï fe) O
deeper into the ground, nor rife out of
it. This thé ploughmen call having a right hold of the ground.
It is eaſy to ſce, that this circum- ſtance in the trim of a plough is of the utmoſt conſequence to the perfeíion of the inſtrument. We ſee alſo, in ge- neral, that the plough may get more or leſs hold, by raiſing or lowering the point K, to which the draught-rope is fixed. This is the uſe of the ſhifting pieces of the bridle fixed to the fore end of the beam, which puc it in the power of the ploughman, to trim
où

d dow, [ 1s kept Ww, This as the either 00 iſe out of
having a
circum- s of the eriedion lo, in ge- : more or ering th: ht-rope È : ſhifting the fore put it I 1,{0 tr
oi
Of ihe Sole and Sock. 59 or temper the plough to his mind, Making the bridle bolt too lere both cauſes the plough to riſe out of the ground before, and cauſes the heel to preſs more on the bottom of the fur- row than is necefſlary, and alſo cauſes the hindermoſt and upper part of the mouldboard to preſs too hard on the earth, at quitting it, which is produc- tive of bad efectsin moiſt clay ſoils, by
caſting the earth into a ſolid clod. No
. more ſhould be done than what is juſt
neceſlary to make the plough go ſteady, by keeping the heel gently preſling on the bottom of the furrow.
From the account here given of the operation of the plough, and the vari-
ous reſiſtances to which it is expoſed,
EZZ)
it is eaſy toinfer, that the proper place
of

60 Of the Sole and Sock.
of the point of draught at the fore end of the beam, muſt depend on the form of the plough, both with reſpect to its ſock and mouldboard. A plough, of which the ſheath has little inclination or rake forwards, being leſs preſſed down before, will reguire the point of draught to be higher than a plough of another make. Thus ic appears, that when a plough is already made, its hold may be regulated by the place of the point of draught.
On the other hand, a plough, whoſe point of draught is fixed, or cannot be ſufficiently changed, may have its hold regulated by the make of its ſock and mouldboard; for theſe two things, the place of the point of draught, and the make of the plough, have a mutual de-
pendence,

ore end ne form tto its 10h, of ination preſſed point of ugh of rs, that de, its
ee af
1, whoſe annot be e 1s hold ock and 1095, the
and the utual de-
pendenC
Bf the Sole and Sock. 6E pendence, and neceſlary connedlion with each other, This laſt method of re- gulating the hold of a plough depends cn the form and poſition both of the ſock and mouldboard. Pointing the ſock downward will increaſe the hold of the plough, and raiſing its point will diminiſhit. Alſo, by inclining the ſheath much forward below, we increaſe the hold. of the plough, and by making the ſheath more upright, we diminiſh its Thus a plough may have hold both by the ſock, and by the make of the plough.: Le is plain; therefore; that theſe may be fo adjuſted as to give the plough a proper hold on the whole, and a plough, which has too much or too little hold by its make, may be brought to a right temper, by giving it leſs or
IMNMOFYEe

det
62 Of the Sole and Socke more hold by the ſock. But it is plain; that although the exceſs or want of hold by the make, may be balanced or corredted by a want or exceſs of hold by the ſock, and thus the plough be made to have, on the whole, a proper hold; yet this expoſes the plough to op- poíſite flrains, and increaſes the labour of the cattle, and that the plough will be more perfect, when the hold by the ſock and by the make both agree. This will alſo be attended with the advan- tage of making the upper part of the ſock and the mouldboard of one regu- lar twiſt, which will give the eaſieſt turn to the furrow, and leave it in the beſt ſtate.
It would appear, that the beſt poſi- tion of the ſock is to have its under
ſurface

1s plain; ant of ced or of hold ugh be A Proper 1 to OP- labour "1h will by the e, This - of the ſE TEQU- e ealielt
t in the
Of the Sole and Sock. G3 ſurface even with the plane of the ſole. But experience teaches us, that a plough goes more ſteadily when the ſock pro- jets a little below. The reaſon ſcems to be this: When tlie ſock and: ſole are in 9ne plane, and the point of the
ſock meets a ſmall ſtone, it cannot get
below it, becauſe the ſole is then on the
firm ground. The plough muſt there-
fore paſs over this ſtone, and loſe parc of its hold. Or, if the reſiſtance of the ſtone againſt the upper part of the ſock forces down the point, the heel muſt im- mediately riſe; whereas, when there is a ſmall proje&ion downward of the ſock, a little hollow is left under the fore part of the ſole of the plough, which* allows it to ſink a little deeper, and thus throw up the ſtone, and, at the ſame
time,

6A Of the Sole and Sock.
time, does not neceſlarily force up thé heel. AlI this may be done with a ſock of a regular twiſt, and proper length and ſhape on its upper fide, by making the point of the ſock about five eighths of an inch below the plane of the ſole, and bringing forward the plane ofthe ſole as much as poſfible, ſo as to leave no conſiderable hollow betwcen it and the ſock.
This beiúg done, the tempering of the plough for its hold muſt always be produced by means of the ſhifting parts of the bridle, which the ploughman can vary in an inſtant, agreeably to the na- ture of the ſoil in which he is working. A well-conditioned plough will always allow this, and if a plough cannot be tempered in this way, it muſt be tem-
ered
pry

€ Up thi h a ſock length making e clohths the(ole, ne ofthe to leave
it and
rns of ways be ng parts man call o the n vorkIny illalways not be be té
ered
I
Of the Sole and Sock. 65
QQ
peredibyghe ock Buti.as vas ſaid béſore. ſuch a: ploueluis: not. perfedt, but has an exceſs of hold in one part, balanced by a want of it in another. Ît may be known when a plough is perfeét in theſe.reſpeds:;- Let the point oí draught be fixed as high as the bridle will admit, and let the plough be work- edin even light ſoil, free of ſtones, and take a good furrow.. The heel of the plough ſhould not preſs on the ground at all, but ſhould even riſe a little. Then let che point of draught be fixed as low as poílible. The heel of the plough ſhould then preſs hard on the ground, and the plough ſhould even ſhow ſome tendency to come outoîf the ground If theſethings do not happen, we may be certain that the poſition of the beam is not properly adjuſted tothe make of the plough, and
I the

66 AE the Sole and Sock. the poſition of the ſock, and we can now temper the plough by the ſock, ſo as to bring it into thé condition deſcribed above.
Ic may be obſerved in general, that the point of draught muſt be fixed 2 little below the ſtraight line drawn
from the lower end of the backband to
the lower end of the ſheath behind, be-
cauſe, in moſt ploughs, the centre of
action is not far from this‘part of the fheath. The diſtänce of the points H and K, ſhould neverexceed four inches. Buc this matter, together with another method of tempering the plough for the hold, by yoking the cattle more or leſs forward, will be confideréd afterwards, when we come to ſpeak more particu
larly of the framing and putting the

eral, that Ye fixed y
dramn band to nd, bet ntre of \ df he voints[i ‘inches, another h for the e or led erards, particu- ing the
plough
%
Of the Sole and Sock. 67 plough together, and of the manner of yoking-
Ic may, however, be added here, that
the length of the beam has a great efect
in making the plough go more ſteady,
even when, in every thing, it is ad- juíted as above deſcribed. DireQions will alſo be given afterwards for adjuſt-
ing all ploughs to the ſame hold, what-
ever 1s the length of the beam.
Beſides the adapting the ſock in the manner now deſcribed, for giving the plough a proper hold of the ground, we muſt alſo conſider its poſition, which is molt proper for keeping the plough in che ſtraight direcion forward. It ap- pears to me, that the moſt proper me- thod for obtaining this end, is to make the land ſide of the ſock even with the
reſk

63 Of the Sole and Sock.
reſt of the land ſide of the plough, and
to make the whole of its taper on the furrow fide. Itis, however, a very uſual pradétice to ſet the point of the ſock alittle to the: right. The reaſon
given for this 1s, that the reſiſtance may
be diminiſhed by ſharing it between“
the two ſides. But this reaſon is inſuf- ficient, when the ſock is of the proper form, and this poſition of the land ſide of the ſock produces very bad efffeds. Itis Verytrue, that fa ſock of the form in figure Io. were drawn in the direction of A H, inſtead of being drawn in the direction of IL, and if it had a part on both ſides of the point I, egually formed for cutting, the refiſtance to its
motion would be diminiſhed. But, in the
firſt place, this reſiſtance is but a ſmall
part

18h, an on the » A Very t of the € reaſon
ance(MAY
between
s Infuf- proper nd füe eileAs, cof the in the & drawn i had a equally cé to its t,in the q ſmall
part bh
Of the Sole and Sock. 69 part ofthe whole reſiſtance of the plough. In the next place, this form of the ſock. at the point, will not agree with the good property, which a ſock ſhould have, of making a fair ſurface with the mould- board, and thus beginning the opera- tion of the plough, in turning over the ſoil, as well as cutting and raifing it. Now, if the ſock is made of the proper form for thoſe purpoſes, that is to ſay, thick or perpendicular on the land ſide, and wichout a cutting edge, the refſiſt- ance will be increaſed, inſtead of being diminiſhed, by thus turning the point of it to the furrow ſide, becauſe, then the land ſide of the ſock would meet the firm ground with a perpendicular ſurface, unfit for cutting, and would be puſhed by it to the right hand, cau-
fing

7D Of the Sole and Sock. ſing the plough to loſe land, as the ploughmen expreſs it.
The bad conſeguences of this poſition of the ſock, even if the land ſide were made fit for cutting, are many and great. When the ſock ftrikes on a ſtone with its land ſide, it muſt be turned off to che furrow ſide, becauſe it cannot force the ſtone further into the firm un- ploughed ground, whereas a ſtone which is ſtruck by the furrow ſide of the ſock, is very eaſily forced into the open furrow. This poſition therefore of the ſock, even when cutting on both ſides, cauſes the plough to loſe land, and this bad effet muſt be balanced by ging the plough a greater tenden- cy to the land by the form of its other parts, which muſt increaſe the reſiſtance
to

o
d, as thi
sDofition ſide were and great, tone wih d of to 10t force rm un- 1 ſtone ſide of into the herefore on both ole land, nalanced tenden-
ts other
ſiſtance
[0
Of the Sole and Sock. D to its motion, or it muſt be balanced, by fixing the point of draught more to the right, which occaſions a ſtrain on
he beam, acroß ît, where it is weakeſt,
ais
by the coulter-hole and mortiſe for the ſheath. AlII theſe reaſons, taken toge- ther, give a plain preference to the po- fition of the land ſide of the ſock which f have here recommended.
We come next to conſider the breadth of the ſole, reckoned from outſide to outfideat the heel. With reſpeto which there is great difference of opinion. But an attentive conſideration of the o- Pperation of ploughing will fix our ſenti- ments on this matter. The ſlice which the plough cuts off from the firm ground mult be turned over to a certain degree,
or mult, at leaſt, be ſet on its edge. This

TL Of the Sole and Sock.
Y
can never be done unlels we re=-
move the flice its whole breadth tà the right hand,‘as may be ſeen by 1n- ſpelling figure 9. where A CDB repre- ſents the firm ground from which the ſlice is to be çut. Suppoſe the breadch of this to be nine inches from À to H, the coulter muſt come perpendicular- ly down thro’ H I, and the ſlice A HIB muſt be turned over upon the corner B, ſo that the bottom B I of the ſlice may at leaſt ſtand upright, fronting the un- ploughed ground, and the furrow ſlice ſtand on its ſide& B. Now, it is plain, that when this is done, the whole ſlice is ſhifted nine inches tothe right hand. It is evident, that this can be- done by
no other means, than by giving the
ſole of the plough this breadch behind,

We pe: eadth th N by] Ia D repre- M
\ch the è breadth À tol, 1dicular- AHTB roer Þ, (ice may ° the u0- row Îlice : 18 plain N/S IR À hole flice
ht hand,
Of the Sole and Sock.+ when it leaves the earth, for there is nothing elſe tó preſs the‘earth to the right. When the ſole has this breadth, ic will ſhift the earth completely, and the turning over the ſlice into the defred poſition may then be performed by a proper hape of the mouldhoard. If the ſoil is of looſe mould, which will not re- move by turning over, or will not turn over like cloſe earth, it will fill be re- moved completely from its former bed by a ſole, which is as broad as the fur- row taken by the plough.
I now add, that no greater breadth of the fole is neceflary. I know that a contrary opinion prevails, and thac it 1s ſuppoſed, tha: when the ſole is much broader than the furrow taken by the plough, and by this means removed
K farther

7d Of the Sole and Sock.
farthérito the right hand, theré is the more room made for the next furrow flice! to ſtand on{But thagthis is a miſtake, will eaſily appear, by compar- ing two ploughs, one of which has a ¡ifole of nine inches, and the other of 18 inches, both: employed’ in cutting of. a flice of nine inches broad, and nine in- ches deep. The narrow plough removes the firſt ſlice nine inches to the right hand, and ſets it, as we ſhall ſuppoſe, on its edge. When it cuts of a ſecond
ſlice, it alſo removes it nine inches, and
ſets it on its edge. Therefore the ſecond:
ſlice is ſet cloſe to’ the firſt, becauſe its thickneſs acroſs, as it now ſtands, is allo nine inches. The broad plough removes the firſt ſlice 18 inches to the right hand, and ſets it on its edge. It
FCINOVES

ther of 18 ng off 4 nne Ín- removes le right \apyole, a lecond hes, and e{ſecond aule its ands, 18 | plough 5 to the 96. Ît
removes
Of the Sole and Sock. A removes the ſecond ſlice 18 inches to the right hand, and ſets it on its edge. Therefore, in this caſe alſo, the ſecond ſlice is ſet cloſe to the firſt, andit has no more room to ftand on than the firſt.
It is not the breadth of the ſole, or the removal of the earth to the right, which gives room for the furrow ſlice to ſtand on. This depends on the proportion between the breadth of the ſlice and its depth. When the ſlice is
as deep as it is broad, it is preſſed cloſe
to the former ſlice, whatever 1s the
breadth of the ſole of the plough, be- cauſe there is no more ſpace than îts thickneſs will fill up. Tf the ſlice is ſtill deeper, it is ſqueezed ſtill cloſer to the former ſlice, and ſo bruiſed, that part O 1E 1s ZIOTCEd Úp:to a Srcater height
than

E——
6 Of the Sole aúd Sock.
than it would riſe to if it had room, When the ſlice is broader than it is deep, wlucly is the common caſe, then it has more room, when ralſed on its edge, than it-can-fill up, and by this means it does not preſs ſo much on the hindermoſt end of the mouldboard, but falls more freely away. But when the ſlice is much broader than deep, it falls nuch over, and is made to lye on its back, which is reckoned a defed in the work, This has been freguently charg- ed as a great fault of the plough with a feathered ſock, and curved mould- board; and it is true, that this has been oftner ſeen in working with this plough than with the plough having a ſpear ſock and plane mouldboard. But this
is Not a defect of the plough, but a fault
of

d room, an 1e js le, then d on its 1 by this n on the ard, but hen the , it falls e on its X 1 the y charg- rh with mould- has been a lpear ut this a faule
a) of
wl
Of the Sole and Sock. 77 of the plouglinian. The feâther‘ſock can‘raiſé a greater breadth of' furrow than the ſpear ſock, and this gives an opportunity, and temptation to the ploughman to make the furrow very broad, in proportion to its depth, and this will neceſſarily lay the ſlice on its back. But the feather ſock plough, with the twiſted mouldboard may, and ſhould be ſo conſtructed, as to turn the furrow no farther over than will allow it to. ſtand on. edge, by: giving-the mouldboard the proper twiſt, and by not. giving the feather ¿too great breadth.
As the diferent ſoils, and the difffe- rent: number of. cattle in. the: yoke, muít require different breadths of fur- TOW no rule can: beeven- for the
breadth

8 Of the Sole and Sock.
breadth of the ſole, which will fit all caſes. The furrow ſhould always be adapted to the ſtrength of the draught. For a draught of two or three horſes, the breadth of the ſole ought not to be leſs than eight inches, nor greater than ten, reckoned from outſide to outſide behind, ſquare over from the land ſide. The only advantage attending a greater breadth of the ſole, is the giving more room for the horſe and ploughman to walk on in the bottom of the farrow-. But it 1s very improper to increaſe this beyond what is abſolutely neceſ- ſary, becauſe the removing the earth ſo much farther to the right hand requires
nearly as much more power, or labour
of the cattle.

| fit all ays be aught, horſes, tto be ter han, outhide 1 fide, reater more An(0 UNO, 1Creaſe
necel- arth lo ¿quires
labour
Of rhe Sole and Sock. 70
Ic muſt be obſerved, that what has been now fid concerning the breadth of the ſole, relates only to the feather fock plough. The ſpear ſock plough difiers in its manner of raiſing the fur- row, and reguires a diferent form and poſition, both of the ſole and mould- board, as will be ſhown afterwards.
The form of the mouldboard ſole, and its inclination to the land ſide ſole, come next to be conſidered.
This has been very frequently form- ed circular, or convex, outward, like the upper part of the mouldboard. But this ſhape does not agree with the beſt manner of turning over the furrow lice, which ſhould be done by equa? degrees, as the plough advances thro? equal ſpaces. As the plough advances
equally

——————————— Es UZ L
89 Of the Sole and Sock.
equally, the earth ſhould be moved e- qually to the right hand, as well as bé equally- twiſted over: This- maxim, therefore, direéts us to make the mould- board ſole a ſtraight line from the point of the ſock, toits hindermoſt end, as is repreſented in fig. 10. where I Lis the ſtraight line of the land fide, and IK is the ſtraight line of the furrow fide, in- terſe@ing each other at the point of the ſock.
The breadth of the feâther iïs the next point of importance to be conſidered. This muſt be in a certain proportion to the breadth of the ſole, and of the furrow ſlice taken of by the plough. Ic alſo depends on the nature of the ſoil. A. ſoil free from ſtones, and full of tough
toats, requires a broad feather; and a
A1
1 LONCyr

CE e Sole and Sock. Sr
Noved e. itovney ſoil, with few roots, requires a llas bi harrower one. We can only mention maxim, the breadth proper for a middle kind € mould- of ſoil, and ſoils of very different quali- he naine tics muſt have the feather changed on end, 8 1s purpoſe for them.
E 0e When the ſole of the plough is nine EXA inches broad, which will fuic extremely deh i well a furrow of eight inches, more or ofe leſs, the breadth of the feather ſhould
be about ſix inches. Ic is very uſual
to make the feather of ſuch a plough
the next
dee, eight inches broad; and this has been portion thought by ſome to be an improvement GWE in the plough, becauſe it makes it to uoh, cut of all the earth from the bottom of N the furrow. Buc this great breadth of LO the feather is attended with two bad ZME eſteis. The flice being completely cut LT
L off
{toney

S2 Of the Sole and Sock. off from its bottom, ſometimes breaks from: the firm ground, before it begins to’ riſe on the ſock and mouldboard. B3r this means, it freguently happens that it 1s' not turned: over by it, but is merely ſhifted away to the right hand, rétaining; its former poſition, with the fame ſurface uppermoft which vas up- permoſt before. But when the feather is two or tliree inches narrower than: the furrow flice, a part of the ſlice on the corner next the furrow is not cut. This keeps that corner of the ſlice faſt till the reſt of it riſes on the ſock and mouldboard; and, by the time that it is almoſt on edge, this corner breaks of itſelf, or is very eaſily broken off by the wider part of the mouldboard ſole, and! then the ſlice does not ſlide to the right,
but

Of the Sole and Sock. 82
break but is properly turned over. The tear- begins ing of this little part occaſions no re- board, ſiſtance that is worth minding. The happens reſiſtance is. perhaps even leſs than what , but 15 would happen on cutting it with the ht hond, feather, becauſe this great breadth of vith the feather would make it cut the earth al- ‘as up- moſt perpendicularly, which is the ſe- feather cond inconvenience ariſing from too rau great breadth of the feather.
Mee Aby On the other hand, I do not think that PA the feather ſhould be much narrower Lee falt than ſix inches, becauſe, when too great Ca a portion of the furrow flice is left un- OL cut, it requires more force to tear it, e and the work is not ſo neatly perform- Php the ed, and the mouldboard is preſſed up, 4 which throws the plough to the left a- N dos bove, and ſpoils the ſhape intended to
i be given to the furrow- hut The

84 Of the Sole and Sock.
The length of the feather ſhould be in proportion to îts breadth. Ten in- ches along the land ſide of the ſock, or 2 inches along the edge of the feather, appears to me to be a very proper length for breadth of x inches. The making ir much longer will leave too little room for bending the ſock plate for fixing into the plough. Tc is plain, however, that the longer we Bile the feather it will cut more ob- liquely, and meet with leſs reſiſtance.
The height of the ſock feather, or its pofition with reſpe&t to the land ſide, is of ſome importance. The outer cor- ner of the feather ſhould be ſquare with the land ſide of the plough, and on a level with it. Tt is true, that by this pofition the cut made by the feather
wil

Of the Sole and Sock. 85
ould be will not be exaly level with the ſole of Ten im tie plough, becauſe the point of the ock, or feather. 1s a little Tower.* Butt E 1s feather, found, that when the whole feather is Proper as much lower than the ſcle as the inches, point is, the plough 1s very apt to run ill leave out of the ground to the left ſide. The le ſock reaſon of which ſeems to be this: The oh, Tt right corner of the feather, and the ger we right ſide of the ſock, are moſt ſtrong- ore Vs Iy preſſed down by the furrow, which Hance, is a raiſing. This twiſts the plough to r, Or Its the right above. If, now, the feather nd hide, ſhould meet with any confiderable re- ter cor- fiſtance, when the point of the ſock is O higher than the right corner of the fea- id on A ther, the plough is apt to run upon the by this edge of the feather, and be thrown out feather pf the ground to the left. On the other
oi y hand,

86 Of the Sole and Socke
hand, if the right corner of the feather is higher than the ſole, it leaves a part of the furrow uncut, which the ſole muſt paß over, and the plough is turns ed over to the left above, unleſs the mouldboard ſole be made higher than the land ſide ſole; in which caſe the work is not performed as it ought to be, with a ſquare bottomed furrow.
I muſt here obſerve, that as the point of the ſock cuts five eighths of an inch below the ſole, for the reaſons given a- bove, it is neceſſary to raiſe the mould- board ſole as much higher than the land ſide ſole, that it may be cleared by the feather cutting before it. But if it be any higher than this, it will not remove all the earth which is cut by the fea- cher.
de

C feathez 4 Dart : O S D M uldboar d. 118 turns EN| ihis forms the furrow ſide of the nlels the
Þlough, by which the furrow flice is re-
rhe Ï Zer Vun moved from that place and poſition
cale ie which it has when cut by the coulter ught co and ſock, to the place and poſition DN which it has when finally left on the point ploughed land. This part of the plough wm nch has been long neglected, the whole in- given as ſtrument having been conſidered as un- mould. worthy of the attention of perſons ſkil- the land led in machinery, who were apt to ima- ] by the gine that no rule was neceſſary for the if ic be conſtruction of ſo ſimple an inſtrumenc. remove Thus it has been left in the hands of he fear_ unſíſkilful country artiſts, who, having
No juſt principles to guide them, could
0)\ neither

88 Of the Mouldboard.
neither judge of its defe(ts, nor of tlie
means of its improvement. But it may be affirmed, that the conſtruction of the plough, eſpecially of its mouldboard, is of a very nice and complex nature, and requires conſiderable ſŒill to make it in ſuch a manner as to perform its work to the wiſh of the ploughman, and with as little labour as poſlible to the cattle. I may alſo affirm, that with reſped to the propricty of the work, ploughs of the moſt approved conftruction, and which have a great character, fall ſhort of what a plough may be made to per- form, in a proportion not leſs than that of three to four. And, with reſpedt to the reſiſtance, I may alſo venture to
affirm, that with the ſame ſize of fur-
row, and the fame finiſh of the work, theſe
E EEE

00r of thi
But jc 2
tion of the lWboard, is
ture, and 0 makeit in 1 its mol and with he cattle, eſpe to \005hs of tion, and fall ſhort Je to pe! chan thu! ceſped{0 enture t0 Ta of{ul che work,
chel
Of the Mouldbodrd. 00 theſe ploughs will give às much labour to three hidrſèts as a better adapted plough will give to two.
The form of the mouldboard muſt have three properties. It muſt keep the plough to a proper hold of the ground; it muſt remove the earth to the furrow ſide, and it muſt turn it over.
1/è, Ic is by the back of the ſock, and the fore párt of the mouldboard, hay- ing the furrow ſlice lying upon them, that the fore part of the plôugh is kept in the ground. Therefore, the weight of the furrow will llave the more power to keep the plóugh in the ground, in proportion ás the bâck of the ſock, and fore part of the nmiouldboard, are more
below it. The plough will alſo keep.
the ground ſo much the better, in pro-
M portion

99 Of the Mouldboard.
portion as the carth ceaſes more gradu- ally to preſs down the mouldboard, as ït 1s turned over.
In the next place, as it is by the back of the ſock, and by the mouldboard, that she earth is removed from its firſt poſition, it 1s plain, that the nigher that the back of the ſock can come to a plane parallel to the ſurface of the ground, and the greater breadth of furrow that can be lying on the back of the ſock at once, the better will the un- der ſurface of the furrow ſlice be raiſed. It is plain too, that in propor- tion as we make the twiſt of the ſock and mouldboard more gradual, from: the point and edge backwards, the fur- row will be raiſed with leſs riſk of crumbling, and with leſs labour to the
cattle.

01e Prad:
board, 4s
[the back vldboard, om 1 Fuſt tgher that ME(0 4 : of the adth of back of I the un- (lice be propor- the ſock 11, from the fur- ‘ilk of ECO the
cattle»
Of the Mouldboard. 9L cattle. The more dire that the ſur- face of the back of the ſock and mould- Doard is for leading the carth from the one poſition to the other, it muſt be ſo much the better for taking the quantity of furrow which is cut by the coulter and ſock all together, whereby there is a greater quantity of earth brought up from below, and made part of the new ſurface: But when the ſock and mould- board are of ſach a make as to have little breadth below the furrow, and that little of an abrupt, or irregular form, there is but little of the lower part of the furrow made to become part of the ſurface of the ploughed land. In land where the ſoil is neither clay, nor free in riſing, but looſe, or bound with deep roots, the plough of ſuch a
make

92 Of the Mouldboar d.
make cannot raiſe above half of the
furrow which is cut of by the coulter and ſock; but, inſtead of this, puſhes a quantity of earth to the right, leaving the former ſurface ſtill uppermoſt, and covering that part of the furrow which ſhould have been raiſed. There is a plough made with an iron head, and ſpear ſock, without a feather; and made with ſuch a degree of land, or tendency to the left, as to reguire the being held over to the land ſide above, in order not to run jnto it. Tn this poſition of the plough, the ſole of the mouldboard behind is nearly as high as the ſurface of the ground; the back of the ſock being very narrow, raiſes ſo very little breadth of furrow, that the mouldboard could not follow it, if it were nat ſo
high.

I of the 1 coulter ) puſhes 4 » leaning
mod, and
row which,
here 1s 2 cad, and 1d made endency eing ned in order ſition of uldboard : ſurface he ſock ery little ¡ldboard e nat(9
y 9.
Of the Mouldboard. 93 kigh. Such a plough can only make a triangular rut, and raiſes no more earth than what lyes in the angle be- tween the coulter and mouldboard ſole, in the poſition in which the plough is going, and this earth is turned over upon the firm ground left to the right hand untouched, and covers it, ſo that the whole appears to be turned up.
In the next place, the earth is to be removed to the right hand. If this were all that is to be done, the moſt proper form of the plough would be a half wedge, with its fore edge perpendicu- lar, moving in the cut made by the coulter, and having its land fide applied cloſs to the firm ground. Such a plough would remove all the earth to the right hand, keeping the ſame ſurface upper-
moſt which was uppermoſt before. The

94 Of the Mouldboard.
The power reguifite to draw this plough
forward diminiſhes as the thickneſs of the wedge is leſs in proportion to its length, or as the plough is longer in proportion to its width. It is true, that Mr Baron, in his treatiſe on rhe, plough, denies this, and ſays, on the contrary, that a ſhort wedge is more ealily drawn than a long one. He alſo ſays, that when he made experi- ments with different wedges drawn through ſand, he found the reſiſtances to be proportioned to the length of the wedges, and he aſcribes this to the greater time which the ground has for preſſing on the longer wedge. It is very true, that when the wedge is longer than another of the ſame thick-
nefs, it is at any one time employed in
re-

/ q
this Plough ickneßs of tion to its è longer in ky tue, tile on he s, On the 1s more 16 Ve * experi- 2s drawn eliltances th of the 1s to thi nd has fo! oe, 1 18 yedge 18 ne thick- ployed iN
ré
Of the Mouldboard. OS removing more earth, in proportion to its length. If therefore, a plough were working in mere ſand, or in ſoil as looſe as ſand, and had nothing to do but to ſhift this to the right, little ad- vantage would be gained by making it longer: But, in foils which have any confiderable coheſion, the furrow ſlice muſt be cut and bent aſide. In the per- formance of which, there is an advan= tage attending a very long and thin wedge, as well as in all caſes of cutting
nd cleaving inſtruments. It is very difficult to ſay what is the proportion in which the advantage will increaſe; but I may venture to aſſert, that it will at leaſt extend to that length of wedge which is neceſſary for giving ſteadineſs
to the plough?’s motion.
CJ cd T4 1

g6 Of the Merlatoürd.
Ic has been ſuppoſed, that by making
the wedge round on the furrow fide, if would require leſs power to draw ié forward; and this ſuppoſition has been juſtied by obſerving the advantage which a ſhip has by being of this form. But there is very little reſemblance be- tween the refhiſtance of the water to à hip, and the reſiſtance of the earth to a piough. A ſhip rnoves more eaſily, by
being rounded in behind, becaufe, by
this means, the water falls in more caſi<
Ïy to fill up the ſpace left by the ſhip. This, with other reaſons, renders that form the moſt proper for a ſhip.
But, in ploughing, the earth is not to fall in behind the plough, and, if it did, it could not help the plough’s motion.
[It is true, by rounding the wedge back-
wards,

},
by malig ow fide,| 0 draw jt 188 been avantaog 0)
f fh iq, blance b: ater to i arth to a alily, by Gaule, by more cali: che(hip. ders tha! IP,
18 Nt 10 „Iifitdid, motion, Ilge back-
wards,
Of the Moutdboard. 07 wards, tlie reſiſtance of its hindermoſt Pat{15 diminiſhed; bat its uſe in re- moving the earth 1s diminiſhed in the very ſamé proportion; for the wedge will not remove the earth but in pro- portion as it widens behind. If, there- fore, the wideneſs of the wedge behind is ſpecified, it will remove the earth to the ſame diſtance, whatever is the round of its furrow ſide; and the only efect of rounding this ſide, is to make it re- move thé earth more ſuddenly with its fore: parts. This ſhapes, therefore, ſo far from diminiſhing the refiſtance to the plough’s motion, ſeems rather to in- ércaſé it, becauſe it makes the fore part of the plough act like a wedge of a more ſudden taper. Each part of the plough would ad like a wedge, tapered in the
N ſame

93 Of the Mouldboard.
ſame direction in which a plane board
would Iye when it touches the plough in that part. Beſides the increaſe of reſiſtance, the wedge of this rounded form would be more apt to break the furrow, without removing it regularly, than if it were ſtraight in the ſide. Ic is plain that theſe inconveniences mußt be ſo much the greater as the round of* the ſock is more forward.
On the whole, therefore, a ſtraight ſurface is the moſt proper ſhape for the furrow fide of a wedge, whoſe only office is to’ remove the earth tothe right hand.
But, as the earth muſt be raiſed up, as well as ſhifted to the right hand, the
form of the wedge muſt be diferent
rom that now deſcribed, and muſt re- ſemble

ne boa Plough reale of rounded ak the egulary, lidé, I: es muſt
und of
\
{rohe
ape tor le only
he right
ſed up, nd, the ferent ult re-
ſemble
Of the Mouldboard. 99
Tæmble fig. 7. No. 2. Suppoſe a trian- gular block of wood, G F DE, of which the hindermoſt and back edge GF is perpendicular, and whoſe lower back edge FE lies in the angle formed by the land fide of the plough and the ſole, and whoſe baſe FD Eis a triangle, ſquare at F, and Miarp at E, and whoſe breadth F D is the breadth of the ſole behind. Suppoſe now, that this block were cut through level at the height A B, the lower part of it will form a ſort of wedge ACB EDF. When this wedge is drawn forwards, in the dire@ion 7" E, with its back ſurface A FEB pref- ſed cloſe to the firm land, the fore fſur- face BE DC, will ſhift the earth to the righc, and at the ſame time raiſe it. Ac- cordingly this is very nearly the form of

100 Of the Mouldboard.
of the mouldboard oftheScotch plough,
But there remains another oflice for the mouldboard to perform, namely, to turn over the furrow ſlice. This will not be performed by either of the wedges Abeve Gelcnibed. Tf mag! be here ſaid, that the Scotch plough does really turn over the furrow. It daes ſo, but for the following improper rea- ſon. The plough is kept over to the land above, and the wreft, or mould- board ſole, riſes conſiderably above the land ſide ſole. By this means the plough leaves a ſmall ridge of untouch- ed earth between the bottom of the fur- row in which it is going, and the bot- ton of the next. When the ſtraight mouldvboard has ſhifted the earth to the
top of this ridge, it cannot remain there,
but

Of the Mouldboard. TOL hh Plough, but falls over on the next furrow. The oflice fy plough, by this, appears to make good
namely, work, but this is only an appearance, Tvill becauſe there remains under every fur- er df the row a ridge of carth which is not turn- t my le ed up.
ugh does Since then it appears that the three It does fold motion which muſt be given to the Per rea- earth, namely riſing, ſhifting to the ‘to the right hand, and twiſting over, cannot moulds be performed by means of a fſtraighce bove the ſided mouldboard, whatever poſition we 10s the give it, we muſt have recourſe to a untouch- twiſted mouldboard, or one of a curved {the fur form. Accordingly mouldboards have he bue long been made with a curve or twiſt. ſtraight Théſe have differed very much in their dito the ſhape, as they came from the hands of in ther, different artiſts, Such perſons, being
BA guided

E EZEEE ZEITZ TET E E E A E pT 5 LA PEE EE E E
LO0Z Of the Mouîdboard. guided by no principle, could not be
expected to follow any one rule. But the operation of the plough is a certain thing. The earth is found by it in one place, and in one poſition, and muſt be left by it in another place, and in aGoilies poſition. If the farmers are once agreed as to the place and poſi- tion in which the earth muſt be left, there is ſurely but one way in which this can be beſt done, and therefore, when all ploughs are made ſo as to do this, their mouldboards will be of one form.
With reſpec to the firſt, it ſeems to be the opinion of the moſt ſenſible far- mers, that the earth ſhould be ſhifted about nine inches to the furrow ſide,
2nd that the furrow ſlice ſhould ſtand
with

d not hy le: Bu a Certain lt in one nd muſt €, and iq ers are nd poſi: be left, Which ereíqre,
as to do
» of one
ſeems to ble far- : ſhifted dide,
d ſtand with
Of the Mouldboard. TO3 with that ſide which was formerly un- dermoît now fronting the land ſide, and leaning back to the furrow fide about forty degrees; ſo that the furrow flice muſt be twiſted from its former Ppo-
fition about 120 degrees. This plainly
ſixes the poſition of the hindermoſt part
of the mouldboard, where it quits the furrow. If any other poſition of the earth is found by experience to be Pre- terable to this, it is eaſy to vary the mouldboard accordingly. My buſineſs îs not to inſtruit the farmers what ſhould be the poſition of the earth when left by the plough, but to make 4 plough which will leave it in the polſi- tion which their beſt judgements ap- prove. The direâ@ions which I ſhall now give on this head, will ſhow thac
INF

——
IO4 Of the Mouldboard. my principles will apply equally well to
any opinion which they may have in this important matters The principle which ſhould direÆ& us
is the following very ſimple one. As
the beſt way of ſhifting the earth to one
ſide, or of raiſing it, is to ſhift it, or raiſe it, by equal degrees for every inch that the plough advances, ſo the beſt way of turning it over, is to give It equal degrees of twiſt for every inch chat the plough advances. If it is more ſuddenly twiſted in any one part than another, more force is regúuired at that part, and the furrow fſlice-1s more eXx- poſed to the chance of breaking in that
part, by which the regular poſition in
which we wiſh to leave ic is deſtroyed.

ly well Y
/ have ju
| diret ys eme, As arthto one (hift it,« Very ind 0 ths beſt 0 give It very mch Fit is mOIt part tha! red at th! 5 more dl ng in tha polition ll leſtroyed.
TI ¿ T hg 1488
Of the Mouldboard. 10
SL
This being the principle, IT proceed to give directions, by which any work- inan, of common undérſlanding, may infailibly make a mouldboard which ſhall perform its work as deſired, with- out ever having ſeen one before, or be- ing obliged to copy. The directions will alſo Help him to make a mould- board which ſhall differ from the one to be here deſtribed in any manner he pleaſes, ſo as to perform the work with certainty, in any manner which a farm- êr ſhalt défiréi
It follows, from the principle now laid down, that the momént the furrow is cut by tlie ſock, and begins to riſe on its back, it ſhould alſo begin to ſhift and twiſt to the right hand. From this ic‘follows; that the back‘of the: ſock
Q and

i—————=——— E
706 Of the Mouldboard.
and mouldboard ſhould make one con- tinued fair ſurface, without any intér- ruption, or ſudden change."Fhe twiſt, therefore, muſt begin from nothing, at the point of the ſock, and the ſock and mouldboard muſt be formed by the very ſame rule.
In the next place, there muſt be ſome certain line of the furrow, on which we muſt always reckon the twiſt. This muſt certainly be reckoned on a line drawn ſtraight acroſs the furrow, ſquare
with. the land. ſide Eet us ſuppoſe,
that the plough has juſt entered on a
ridge, which has been cut ſquare a- croſs, and has advanced till the heel nas juít entered the ridge. Then RID in fig. 13. will repreſent the ſod as it
then lies on the ſock and part of the
mould.

Of the Mouldboard. LOT
Ome cat mouldboard. RI is the ſide of the ſod ny inté: which was cut by the coulter, and R D fe mif, will repreſent the end of the ſod as ict oting, at was cut acroſs, while lying in the ridge. è ſock md Therefore the angle R is exaQly ſquare, d by thy- and the angle D is within the ſquare about I6 degrees, when the length from
be lome the point of the ſock to the heel is 33 fhich'we inches, and the breadth of the ſole is «This nine inches, which is nearly the uſual 1 A line dimenſions. This angle D continues y, lquare the ſame frem the time that the point ſuppole, of the ſock begins to raiſe and turn the ed on ê ſod, till the heel paſſes the end of it at quare æ DR. As the plough advances, the angle he heel! approaches nearer to the ſquare; but, n RID we may, without any material error, d as it ſuppoſe, that it never changes from of the the-time that the plough begins to raiſe ould the ſod till ic quits it, This ſuppoſi-
tion

| |
BH
-_F M (A
108 Of the Mouldboard.
tion is very near the truth, and#will give us very eaſy methods of forming: the mouldboard. I ſhall point out tw@- methods for this purpoſe.
The firſt is by means of a protractor and ſcale,
The protradtor is a ſemicircle, divi- ded as uſual into 180 degrees. It is re- preſented in figure tI. and has an in- dex or pointer BO A moveable round the centre O. One of the radiuſes O C is made to project to a convenient diſ- tance beyond the circumference. The uſe of this inſtrument is ſimilar to that of the common ſuit-ſtock, uſed by car» penters and joiners. If the pointer A be ſet to any number of degrees, ſup- poſe 50, then the angle made by the
edges C O, B O, will alſo be 50 degrees,
and
-
a0 li bed N] zd huts (he 39)
vis

and
Fe d Þ forming
QUE twa
Drotraßor
cle, divi [t is re- an 1n- è round ies 0 C ent dil ce, The r to thai ] by car ointer À ces, lup- : by thé degres,
and
Of the Mouldboard.| IO9 and a piece of wood may be worked to this bevel,‘by applying it ſquare over to the edge of the piece of wood. The piece of wood may alſo be worked to any twiſt. Suppoſe, that it is required to be twiſted, in ſuch a manner, that it may be ſquare at one end, and half ſquare at the other. Let one ſide of the piece of wood be planed flat, and with a ſtraight edge. Let it be divided along this edge into 45 equal parts, make the mark 90 at that end, where the wood is to be ſquare. Mark the firſt diviſion 89, the ſecond 88, the third 97, and ſo on, till you come to the end, which will be marked 45. Now, ſet the index of the protraor at 90, and ap- ply the angle COB to the piece of wood at the mark 90s ſquare- wich its
edge,

ij N |
LIO Of the Mouldboard.
edge. Let the wood be worked off“at*
that place till it juſt fits the anglé off
the protractor. In like manner, ſet the index at 89, and apply the angle COB to the mark 89 upon the piece of wood, ſquare, over its edge, and let the wood be worked away till it fits the angle in that place alſo. Proceed in this man- ner with all the different degrees of the protractor between 9o and 45, and the correſponding points on the edge of the
piece of wood. It is evident, that by
this means the piece of wood will be
formed, ſo that the wrought ſurface ſhall have a twiſt, from the ſquare to the
half-ſquare, increaſing gradually from
one end to the other, and every part A"
of its length has a gradual increaſe of
twiſt. We may alſo vary this twiſt in
ANY,

, ked of y Wld‘of Er, ſet the gle(0 R (è Cw, & the wood angle in 11s man- es of the and the \ge oî he , that by [ will be t ſurface areto the ly fron very part creaſe 0f wiſt in
any
Of the Mouliboard. Últ ny manner we pleaſe, making it more fudden in one part than another. This will be done by making the ſpaces a- long the edge unequal, namely, fmall- er where the twiſt ic intended to be more ſudden, and wider where ict is in- tended to be more gentle,
The other inſtrument is the ſcale, re- preſented in figure 12, which is ne- thing elſe than a piece of hard wood, Planed flat,"and ſtraight, and divided into any number of parts, equal or un- equal, according to the nature of the twiſt which the piece of wood is to have. The only uſe of this ſcale is to ſave the trouble of dividing the edge of the piece of wood to be twiſted. Te 1s of uſe, therefore, only in theſe caſes
where we have occaſion to make ſeye-
i ral

«72 Of the Mouldboard.
aA:
ral pieces of wood of the ſame dimen- ſions, and of the ſame twiit.- To uſe this ſcale, the edge of the piece of wood muſt be worked flat and ſtraight;‘and in fuch a poſition that there may be wood enough evéry where to complete the twiſt. The ſcale muſt now be fixed to the piece of wood witlz pins or crews, in fuch a manner thay its different divifions may correſpond to thoſe parts of the edge where the twiſt is to be, of thiat number of degrees which is expreſſed by the diviſions.
In order to apply theſe inſtruments to the purpoſe of forming the mould- board, another circumſtance muſt be attended to. It was obſerved beforez that when the ptough has advanced thé
whole lencth of its ſole, a line draws © d
ſquare

rd, lame dima iat ofthe Piece d fit and politan that every whe cale mi vood wit nner thay vrreſpond were Me of degrees ſions, nſtrumen! che moult e mult| ed before anced ine dr
1 ql (qu L
Of thé Mouldboard. ô IT3 ſquare acroſs the furrow ſlice, as it then lyes upon the mouldboard, does not make a ſquare angle with the mould- board ſole, but falls about 16 degrees within the ſquare, making an angle of about 74 degrees. For‘this reafon, it 1s neceſlary, that when the edge B O of the protractor’s index is applied ſquare to the edge of the mouldboard ſole, the plane ſurface of the protractor fhall not be ſquare with that edge, but make an angle RDI of 74 degrees.(ſce fig. 13.) For this purpoſe, the tail of the index BO muſt not be a ſquare piece, but bevelled to 74 degrees, as is repreſent- ed in figure 11. No. 2. where BEF G is the index ſeen endways, having its two angles G and E of 74 degrees. The protractor Á C goes ſlanting through it, “ P and

Ï T4 Of the Mouldboard.
and turns round the pin HO, which 1s fquare with the ſides BG and EF. By this means the protra@or A C will make an angle of 74, degrees with the upper edge of the index B E.
The protractor, with-this change be- ing applied as above dire¿ted, with its index ſquare with the outer edge of the mouldboard ſole, will always give the proper twiſt for the furrow, reckoned direâly acroſs it.
Now, let C, fig. 13. be the hinder- molt point of the mouldboard above, and let ID E be the ſtraight edge of the mouldboard ſole, or rather of the ſcale fixed tO it, and Tet E be: the point, tô which the index of the protractor is ap- plied ſquare, when the ſide CO(fig. 11.)
being opened to 1290 degrees, juſt
touches

di,
0, which; dE FP, Bi (will make
ht the Upper
Change ha
d, with iu loe of the give the
reckoned
he hinder. 1rd above, edge of ilt {che ſcat point, 10 ador is ap- )(fig, 1 ree ju
(guchs
Of the Mouldboard. ITS touches the point C of the mouldboard. (fig. 13.) Meaſure the length from E to the point of the ſock, and make this the length of the ſcale,(AEGE2 E Die vide this ſcale into 1 30 equal parts, and number the tens as in the figure 12. Now, let this ſcale be applied to the ſtraight edge of the mouldboard ſole, and there fixed with ſcrews, ſo that the beginning of the diviſions may be at the point of the ſock, and the diviſion 130 will thèn' projet a good way be- hind the mouldboard. This is repre- ſented in fig. 14. where CI is the land ſide ſole, C is the point of the ſock, and CB is the ſcale. The protrador being applied to this ſcale, in the manner a- bove dire&ed, will regulate the mould- board to one uniform twiſt, from its
hinder

LI Ó Of the Mouldboard.
lindermoſt point to the very point of
the ſock, forming at'once the mould- board itſelf, the fore edge of the ſheath, and the back of thé ſock.
In ufing theſe inſtruments, we muſt always be caréful to apply the edge of the index iquare with the edge of the mouldboard ſole; and the part of the ſcale which projets behind the ſole muſt be ſupported, ſo that it may not be preſſed out of the ftraight by applying the ſcale‘toit. Negleétiin! citherof theſe particulars, may produce great crrors in the form of the mouldboard.
It muſt now be obſerved, that the di- rections here given require a corre@ion, on account of the plating with which che mouldboard is to be covered. This
may be done by altering the diviſions
of

BU ld,
ery Doint y the mould,
the ſheath,
(5, we muſt the eda dge of th art of the e ſole muſt y not be y Mug 1 either of luce great uldboard, that the di orreCtior, vih which red, Th + ividons
(
|
Of the Mouldboard. L177 of the ſcale in the following manner: The ſcale being four feet long, it is di- vided into 130 parts, which anſwers to the 130 degrees of twiſt, and it is mark- ed at every five. This makes 26 prin- cipal diviſions, each foot having 657. Set off the firſt 20 diviſions from C to H, (fig. 14.) the ſame as if the whole ſcale were divided equally, and put the mark Do at FeitiSet of aS inches: from Hito A, and put-the mark 26 again at A; Sect off 87 inches from A to D, and put the mark 50 at D, and divide the ſpace AD equally. Set off 55 inches from D to E, and’put the mark 65 at E. Let
the diviſions between 50 and 65 gradu-
“ally increaſe, being ſmalleſt at D, and
biggeſt at E. The diſtance from E to B will now be two feet, and is to be di-
vided

x18 Of the Mouldboard.
vided equally, in the ſame manner as the whole ſcale would have been without this correétion. The blank between H and A is to make up for the difference between the inner and outer ſide of the ſock; and the inegualities of the other diviſions 1s to make up for the different thickneſs of the plating. Alchough the mouldboard made by this corrected ícale has not the regular twiſting of its parts, yet the ſurface of the iron will have that regular twiſt which is intend- ed.
From this deſcription of the inſtru- ments, and of the manner of uſing them, it 1s plain, that whatever opinion
farmers may have concerning the gra-
dual variation of the twiſt which the
plough muſt give the furrow, a mould-
board

nner y T1 Without: betyeen Y : Vference
“fide ofthe
f the her ? different ough the orrelted
1g of its on will
1s Intend-
1e 1nſtru- of uling opinion the grar hich the , mould
board
Of: the Mouldboard. tig board may be made by theſe inſtru- ments, which ſhall produce the twiſt which 1s deſired. Accordingly the fol- towing diviſion of the ſcale gives a form of mouldboard which is much approved of. The numbers in the firſt column are thoſe which are to be placed on the diviſions of the ſcale, and the numbers in the ſecond column are the diſtances from the hindermoſt end of
the ſocks

I i 20 Of the Mouldboard. M al : Y | Frets Tuches aM N: 0 MB 2,0=- O o)| 0A N| 20 laits OASE || É 24 A M à JE ALOE AE t 1 50- N O 9+| Ia | GS E ESE| 4 | 05 70-- i 62 ì Y 30-- ES AFE) / N o 2008 N | e ||| TOO— E D E} 4 | IIO E 2 2 of| R 20 ii SS 6 47 | E D: dI | TIS E s 3 9 11 Y / Ÿ E

Of the Mouldboard. T2t The following diviſion of the ſcale
7
alſo produces a mouldboard which has
given great ſatisfaction. Feet. Tuches. ÂÔ-- O o) ES 40 E S ES 7 50== O NOS (o-- I 2 70-- L 6 SO= S LS EO 99=- 2 21 TOO= F 2 Ti TTO E- 3 O 120-- 2 6 I 20-- 4 7
I have already obſerved, that this method alſo forms the back of the ſock, and the fore edge-of the ſheath. But
Q as

122 VE the Mouldboard:.
as it is convenient to know pretty near- Iy the inclination and curve of the ſheath, before it is framed into the beam, I ſhall here give direQions, illuſtrated by fig. 15. The perpendicular height À C of the ſheath, reckoned from the ſole to the under ſide of the beam, at the fore ſide of the tenon of the ſheath, is
27 inches, and its inclination forward
CDi mches The fore fide of
the ſheath may be formed to a circle I D, having the radius D O of 18 inches, the centre O being in a perpendicular above E, whüch is 19 inches from C. This will leave a ſmall ſpace between AC, which is not made up by the ſheath, but this is of no detriment, for if the
ſheath were ſo far forward, working it
to the twiſt would weaken its tenons.
The

Cty Ney è of th 1
the beam,
Vrated by
M, at th (heath, is forward e fide of a orde I 18 inches, jendicula 5 from(, e betwee he ſheath for if the rorking| ts tell
The
Of the Mouldboard. 122 The part of the ſcale before 20 is of no uſe in making the mouldboard, as it is before the point of the ſheath. It ſerves to ſhow the point C, fig. 14. where the land and furrow ſides interſe& each other. The ſcale muſt be fixed ſo, that 20 at À is egually forward with the point of the ſheath, and the edge which 1s uſed for forming the mouldboard muſt be 27 inches from the land ſide at the. point!'of the ſheath; and 232 at E. When the ſhoeing is put on the wood at this ſize, it makes the ſole to be above nine inches, which is abundance of breadth for general purpoſes,
The other method which I ſhall give for fortning the mouldboard, is by an inſtrument repreſented in fig. 17. which we call a bevel, It conſiſts af a ſtraighs
piece

124 Of the Mouldboard.
piece of wood K M, which may be call- ed its handle; and a rod N:-P, fixed in- to it at an angle equal to that which the crofs line RD of the furrow, fig. 13. makes with the mouldboard ſole, namely, an angle of about 74 degrees. The lach AB is faſtened to its upper ſide, parallel with its edge, ſo as to form a ſhoulder, which can be applied to the edge of the mouldbeard ſole. This in- flrument is repreſented endways in No, 2. by which the angle or ſhoulder may be better ſeen.
In order to ſee the manner of uſiûg this inſtrument, conſider fig. 16. where G is the point of the ſock, GL the land ſide of the plough, CRE a line drawn parallel to it, along the furrow ſide of
the ſheath, and CI the furrow ſide of
the

Of the Mouldboard. 125
Y be ed the mouldboard ſole. RA 1s the upper fixed in mould of the mouldboard, drawn to its Æ which proper thickneſs and poſition. This row, fig, upper mould muſt be taken from a pat- dard ſole, tern made by the protractor and ſcale: 74 degrees, Or we may come extremely near the ICS Uppt egual twiſt, by making RA a ftraight s to forn line, ſet on at R, oppoſite to the point ied to the Y, which is two feet diſtant from the This in- point of the ſock. RA muſt make an ys No, angle A RE of 463 degrees. ulder may Now, let a piece of wood be choſen for the mouldboard. This muft be at r of uſihy leaſt eight inches thick, and of the ſhape 16, when repreſented in. fig. 167 Nos 2, The „the land lower edge C H muft be about 223 in-
ne drann ches, thè-height:O P. 1:2‘inches,.the-in>
m fide" sclination forward CP of îts fore fide 7 fide of muſt be 11 inches, and the upper edge (ht 0A

126 Of the Mouldboard. OA muſt be about 24 inches. When
tis piece is joined to the plough, in ſuch a manner that the mouldboard can be worked out of it, it will ſtand in the poſition, fig. 16. A ORB being its up- per edge, and HCDI its under edge. For this purpoſe, it muſt be hewed away with a perpendicular face on the land fide, in ſuch a manner that the loweſt point forward C of figure 16. No. 2. may be at C in figure 16. No. x. which is the interſe@ion of the furrow ſide AI, with the furrow ſide of the (heath CR; and the higheſt point A, behind figure 16. No. 2. muſt fall on A No. 1. The perpendicular face a- bovementioned muſt now apply cloſe
to the furrow ſide of the ſheath, all the
way from C to S. Now, let the mould
CI

- When gh, in ard can din the 8 ifs tp der edge, e hewed : 0n the hat the ure 16, » Nol € furrow le of the point À, fall on face 4- ly clole „all the
: mould Gl
Of the Mouidboard. DAS CI be drawn oû the under edge of the piece of wood, and the mould R A on its upper edge, in their proper poſition, or inclination to each other, as in the figure, and let the fore edge of the ſheath on the land ſide be formed ac- cording to figure 15. Every thing is now ready for applying the bevel.
Lay the ſtock or handle of the bevel along the line GC, the end M of the ſtock being towards G, and the check or angle of the ſtock being applied cloſe to GC; Mde it-back-along: GC, till the rod PN of the bevel comes to touch the ſheath, which it will do at firſt on the furrow ſide. Let the wood be hew- ed away till the rod now touches the fore edge of the ſheach on the land fide. In this manner proceed backwards, al-
Ways

————-
{28 Of the Mouldöoar d.
ways ſliding the ſtock along the draughé CI, and hewing away the wood tül the rod can touch the fore edge of the ſheath on the land ſide. This will form (the mouldboard as far as the top of the ſheath. Proceed in the ſame man- ner, always applying the ſtock to the draught C I, and hewing away the wood till the rod can touch the mould draught R A, drawn on the upper edge of the mouldboard in its different parts.
When this is done, if the ſtock be gra-
dually drawn along CI, and thê*rod
applied to the fore edge of the ſheath C R, and the upper mould draught, the rod itſelf will ſlide along the ſurface of the mouldboard, and will, in every fitu- ation, be perfeâly ſimilar to the cdge of the protractor, and perform the ſame
offices
m) Yi
Ca Lt
= [Y À

F e Ne man
ſ ; A c C0 te
è mould er edge M, « be gra- thê*rod je(heatl 18h, the
réace 0!
Of the Mouldboard. T29
The mouldboard made in this man- ner will hardly diÆer from that made by the ſcale and proträctor, and may, like it, be varied at pleaſure, by vary- ing the form of the fore edge of the ſheath, and the form of the upper mould draught R A.
A gentleman, who has been ſo good as to look over this performance befóré it was put to the preſs, has favoured me with the following obſervations on theſe two methods.
«The method wich the ſcale and pro- « trádtor does not give an equable twiſt “ of. the mouldboard in any part,€ex- “cept juſt atiathe ¿pornt b.: Lhem&
« thod with the bevel is exa all the
RT way from the point of the ſock to I.
“ Both the methods give too much in-
R s« cli-

I 30 Of the Mouldboard.
‘ clination to the furrow after it paífles “ Fand leave it turned farther than “ro degrees.”
As I make no pretenſion to mathema- tical knowledge, T will not diſpute the truth of this‘obſervation, eſpecially as I am informed by my friend, that the deviation from a regular twiſt is not ſo great as to affect the performance of the plough very materially. Beſides, the reader ſees by this time, tliat this me- thod of forming the mouldboard, whe- ther by the protraor, or by the bevel, will enable us to give it a regular twiſt, or any twrlt we pleaſe. W&é have only to vary the diviſions of the ſcale for the protradtor, in ſuch a manner as a ma- thematician(hall dire& for the twiſt re-
quired. If we uſe the bevel; the ma-
thematician
(fat Y
18|

it palle
er than
iathemg- (pute the ecially y that the s not ſo ce of the les, the Ws We- 1rd, whe- he bevel, lar twiſt, ave only e for the
as 4 Md-
«wilt C E
the md-
matician
Of rhe WMouldboard. T3L chematician can inform us what ſhape of the upper edge of the mouldboard will form the whole ſurface to the de- fired twiſt. And I reckon it a matter of ſome conſequence to have pointed out a rule, by which workmen may make mouldboards with abſolute cer- tainty, according to any given prin- ciple, whereas at preſent they are made at random, or by the eye.
The laſt circumſtance to be taken notice of with reſpe& to the mould- board, is the form of its hindermoſt end. This has been greatly varied by different workmen, although there is only one way of making it proper for its work, which is, that all the parts of it ſhall leave the furrow in one inclined plane, This may be very nearly done
1
LE 7

S2 Of 1he Mouldboard.
in the mouldboard now deſcribed, by making the hindermoſt end ofthe ſame curve with the fore end, the curve cutting the mouldboard, all at one length, as in fig. 13. When the mould- board is of any other ſorm, its hinder- moſt end may be formed fſo as to leave the furrow in one regular inclined line, by the following eaſy method, Let two parallel lines be drawn upon an even floor, at the diſtance of the extreme point of the heel of the mouldboard ſole, from the land ſide of the plough, as is repreſented in fig. 16. by the lines G L and QT. Let the plough. be ſet with its land ſide along GL, ſo that the heel of its mouldboard ſole may be at I. Now, let a ſtraight plank, of the ſame breadth with the mouldboard, be ſet
WW 1 L h

bed, by
the ſame
€ CUrVe«
tt one Xmould- ts hinder: 5 o leq ed line, Let two n even extreme ard fole, lh, as 1 nes GL ſet with he hee! ea ff e(ame be ct
with
EIA
Of the Mouldboard. I-33 with its ſtraight edge along the line Q T, but leaning over to the furrow ſide, Let it now be turned round upon the line QT, like a door on its hinges, till it touch the hindermofſt end of the mouldboard, which muft be cut away till the plank touches it from the heel to the top, and ſtands at the proper iîn- clination to the furrow lide. After this deſcription of the mouldboard, and this account of the principle which‘leads to the conſtrucion, it ſeems unneceſſary to draw any compariſons between this mouldboard and thoſe of other forms; and I doubt not but that the reader will agree with me in thinking that this merits the preference. As the deſcription hitherto given of the plough, has all along related to the
plough

———=S
T34 Of the Mouldboard.
plough which has the feather ſock on
the ſheath, it may be thought that this conſtruction is proper for thac kind of ſock, and that manner of framing, on- Iy. But it will correſpond equally well with other ſocks and methods of framing,
When land is ſtoney, the ſpear-ſock is thought to be the moſt proper, and, in this caſe, a plough framed with a head is thought better than one framed in the manner already deſcribed. Such a framing is repreſented in fig. 18. In this framing, the land fide of the ſheath muſt be even with the Iand ſide of the head, and with the land ſide of the fore and hinder end of the beam. This is done, by giving the ſheath a
{lloulder upon the land ſide, both above
and

Ick ¡Mnd, im. a Ted
«lch 212,
> the lide ij of È m, Bo A ge
od
Of the Mouldboard. i235 and below, and not making îts tenon on the land fide, as is uſually praiſed. In this manner, the Upper tenon of the ſheath may be through the middle of the beam, which will give it the great- er firength. Thus the land ſides of the head and ſheath, and ſilt, are in one plane.
Fhe curve of the ſheath and its in=- elination forward, are to be the ſame as in fig. 15. as far down às the upper lide of the head. The plough however will not be materially hurt, although the ſheath has not ſo much curve be- low, which would perhaps weaken the lower tenon of the ſheath, which, in this conſtruction, is more over to the
furrow fide than uſual.
The

j 16 Of the Mouldboard.
[5
The ſtilt may be either offuch a mould as is repreſented by the dotted lines in fig. 18. ſo ás to frame into the hin- dermoſt part of the head, or ic may be of the ſhape expreſſed by the ſhaded part of the figure, with a chock of wood between it and the heel, and an iron bolt through it, as C D. This is a much ſtronger form, and leſs liable to rack. This framing of the plough may be u- ſed either with a ſpear ſock, or with a feather ſock. The ſpear ſock is repre- ſented in fig. 19. which ſhows the ſole of the head and furrow ſide, incli- ned as they ſhould be, when the mould- board is made according to fig. I4- A croſs ſe(@ion of the hindermoft part of the ſock is ſcen at N I, where E B
E AC is the iron work of the ſock, B A
O 1LS

mould|
Pes Il|
1 hin-
31y be
Duded S| 00d Îy jron 3 enc oJrack. 1gIDe U- OMA
repre: els the S incr glnould- I, T4 git part de BD C) BA
® 112
-
Of the Mouldboard. E27 its back, B E its land ſide, and A C its furrow ſide, and CD the ſole of the head. The back of this ſock behind will have very nearly the ſame inclina- tion with the mouldboard of fig. 14. at that place.
The greateſt difference between this and the feather ſock plough is 1n the height of the mouldboard ſole. As the ſpear ſock does not cut the furrow ſo low before the mouldboard ſole as the feather ſock does, the ſole muſt be 17 inch higher all its length. Different ſoils require a variety in this reſpect.
Another difference is, that the point of the ſock muſt not be ſtraight with the land ſide, becauſe, in this caſe, it would be too much to the left, and would not raiſe up all the furrow, when
S the

T7 39 Of the Mouldboard.
the coulter is placed as before direGed,
which is its moſt proper poſition in this plough, as well as in the feather ſock plough.
When the feather ſock is put a this head, as is repreſented in fig. 20. the hindermoſt end of the ſock is as N 5. CA B being its back, and C E üs land ſide. This ſock has nearly the ſame inclination behind with the mouldboard of fig. I4. at that place. As this ſock has a feather, the mouldboard ſole may be made as low as when che ſock is in the ſheath. The point of the ſock muſt alſo be ſtraight with the land ſide of the plough.
A feathered ſock plough witch a head, will admit the ſock to be fatter above
than when the ſock is on the ſheath, by
which
tula: (M:
vn

D cdd,
O0 this
M ſock|
2h this d, he SN 5, TL land alſame blüoard 21(ock E:1n1y »C 15 11 O: mußt
Tide of
(ead, 15boVe 91, by
hich
Of the Mouidboard. 139 which means there is more length of the plough below the furrow before it is turned up, and the plough keeps better in the ground, and ſcems, in this reſpect, preferable to the other, in foils where obſtacles frequently occur, which are apt to put the plough out of the ground.
When the iron head, with the feather iock,is employed,thetwiſt of the mould- board is formed in the ſame manner, but is extended more forward, becauſe
the hindermoſt end of the ſock is ſmall-
Cr.

ars H]
Directions for making Sock Maundrels,
It 1s beſt to have theſe of caſt metal.
This requires a wooden pattern. This, for the feather ſock on the ſheath, muſt be formed to the regular twiſt by the ſame inſtruments which are uſed for
forming the mouldboard. For the ſock
an the head, the pattern is made pro-
portionably flatter, becauſe, in this caſe,
the twiſt 1s extended further forward.
Diredions for framing the Plough. fig. L.
When the ſundry parts of the plough are to be marked for the tenons and mortiſes, they muſt be laid in the poſi-
tion which they are to have when the
plough

Wye,
Tal, Æ This, D muſk y the WW for 4 ſock bipro- 7 ARNE
Teird,
e
| s0ugh 1 and lg pol [yn the
ugh
Of framing the Plough. I4T plough is made. The poſition of the beam for giving the proper hold depends on two things, I /!, the diffferenrt length of the beam, and the height of its fore end aa the plane of the ſole. 24, The inclination of the line of draught. If all ploughs were of one length, from the part which turns the furrow, to the part of the beam by which the cattle draw, the rule for giving them all the ſame hold is very ſhort and ſimple; namely, to place the fore end of the beam at the ſame height above the plane of the ſole. But this rule will not apply when the beams are of diferent len gths. The following me- thod may therefore be practifed.
AB(fig. 22.) is a ftraight batten a- bout 10 feet long. Let there/be a notch,
ſtud, or other mark C, abaut| 3 feet,
6

142 Of framing the Plough.
6 inches from the end A. Make the point H aboie 4 inches farther from A, which, in moſt good ploughs, is nearly the diſtance between the point of the ſheath, and the interſeétion of the line of draught with the ſole of the plough. Draw a line HL, making an angle L HA, equal to the inclination of the draught. This inclination is to be found by direétions which will be given afterwards. Make HM nine feet, and draw the perpendicular‘M L, meeting the draught line in L. Make LG a- bout five or ſix inches, and draw the line GH. Take a ftraight batten E F, and lay it on the line G H, ſo that its middle K may be about four— from H. Let the battens E F and A B be con- nected by a batten A K nailed to both,
which
E

Me the
Ihn À,
Täarly
1! the 3 ine E nh, Cinole DS the è be 1 Aven 39. wd C:ting L5 4 g= the SELF,
13(f 165
f fioamiÿo 7h loue Ll Of framing the Plough, 143
which will keep E F in its proper place and inclination.
Now, let the ſheath be cut by a raould (0 its proper curve forward, and 2 draught made for the ſole, or let it be allo formed on the end which 1s to be the ſole. Let it alſo be marked at’the height, where its tenon is to begin, Let the ſtile alſo be cut to îts propeé nould. Now, place the ſheath with îts ſole draught on the edge of the batten A B, and ics point at the noth c. Place alſo the ſtile in its proper poſition. Thén lay the beam, wich the under part of its fore end, on the edge of the batten E F, and its under ſide on the tenon mark of the ſhéath. Slide the point of the beam backwards or forewards along
.theredge EF, always keeping its under
fide

I Of framing tbe Ploushb. 44(4 B
ſide to the tenon mark of the ſheath, till the other end of the beam projects ſufficiently behind the ſtilt, for giving a:proper length of ténón. The morti- ſes and tenons muſt now be marked,
while the parts are in thié poſition, and
the plough will have its proper hold for! y
the inclination of the draught, And when the bridle is added, the plough will keep its heel well to the ground.
If the plough 1s to be worked with a
bridle and chain, a piece muſt be fixed«.
É.
to the fore end of the beam,‘When it is« laid down for marking, which will make® the part which touches the batten E F/
to correſpond with the ſituation of. the
4 LA
* p e
point of draught in the going plouglh. The part of the batten A B, which is
behind the heel of the plough is for ad-
Me
yd@ br
9 E Ud{ eo
On e
Var he ud( lo|
| Ws:|

Il\grti- IE ved
vlrag AA,
E BN, and
Bi a | 49 fixe d|
(Dn it 154
FF; make!
Of framing the Plough. 145 juſting the height of the ſtilt handles,
This muſt be the ſame whatever is the length of the filt, and for ordinary men, muſt be about three feet two in- ches from P to B.
The aſcent or inclination of the line of draught depends both on the height of the cattle, and the diſtance from the EA gh at which they are yoked. When the horſes are ſtanding in the draught, let a plumb line be applied to that point a of the chain or draught rope which T= Ges threugh the backband. Meaſure
Îthe height from the ground, and the diſtance of the point of the ground
E ug the plummit falls from the point
Vl, three inches behind the point of the
ſheath. When two horſes are going
abreaſt, as one of them is on the un-
4 ploughed

\
146 Of framing tbe Piough.
ploughed ground, we muſt add half the
depth of the furrow to the meaſure ta- ken as above direéted. When one horſe is yoked before another, in ſuch a man ner as to make two aſcents of draught, a-middle between theſe may be taken, if both are of equal ſtrength. If they are not equat in ſtrength, the mediuntz line of draught will be nearer to the draught line of the ſtrongeſt.‘Thus, if H N be the draught line of the hinder- moſt horſe, and HO the draught line of
the foremoſt; andif the draught of the
firſt is ſtronger than that of the laſt, in#
the proportion of five. to four, for in-
tance, make H N five parts of any
ſcale, and HO four parts of the ſame cale. Make N P parallel to H& and OP parallel to HN. Theſe two lines
will
» Rr©

i:: Of framing the Plough. 147
Lulf'de will meer in P, and H P will be che di- Bret.| rection of the medium line of draught. 0 horſe- The framing on the ſheath requires D in only this farther dire&ion in addition Suweht, to what has been already ſaid, namely, Sltktn, tat in order to make its land ſide on É they the ſame plane wich the land ſide of the 1 dium ſole, and, at the ſame time, îts tenon Sole near the middle of the beam, ic muſt us, 1“have a ſhoulder on the land ſde. This | ei TE lG dis exceed 2 of an inch. Laline of The land ſide of the fſtilt muſt allo be Izof the__1n the ſame plane with the ſheath and ¡glalt, in# fle. arbor in: In fixing on the furraw ſide of the LE: adp plough, the, inſide of the mouldboard A né muſt be hewed till ic is reduced to the $‘and thickSeſs of 2, or 22 inches in the Y jiies nuddle, where the little ſtile is to be
vil fixed,

143 Of framing the Plough. fixed. The upper ſide and hindermoſt
end may be made thinner, becauſe they are expoſed to leſs ſtraîn. The mould- board is then fitted on to the ſheath, at its proper inclination with the land ſide of the plough, and the proper width behind. The little ſtiltis then fitted to, and marked for its proper height. The mouldboard being now taken away again, the little ſtilt is nailed to its pro- per place. The mouldboard being a- gain put on as before, the ſtilts are
bored for the rungs, and marked for
the length.

E moſt
they i
M 1d. 5s, at Æ:! ſile
“nth
id to,
«The vay
rro- | 28 Li are
0 for
a oS]
Of the Uſe of a Chain on the Plough.
When a plough is made with ſuch 2 degree of hold as in fig. 24. the point C of the bridle, to which the draught is applied, is kept in its poſition by means of a chain C D, which is hooked to a ſtaple at D, at ſome diſtance behind on the beam. The chain may be made ſhorter or longer by means of the click in the ſtaple D; and by this means, the point of the bridle C is kept in a circle round the centre bolt B, and the plough gets more or leſs hold, according as the chain 1s made longer or ſhorter. When the plough is mounted in this manner, the point of the beam is ſet higher than when no chain is uſed,‘ although the
height

150 Of the Uſe of the Chain.
height of the ſheath be the ſame, as has
been already obſerved in the dire&ions for framing. The ploughmen call this giving the plough greater redd or free- dom. This form of the plough enables us‘to give it greater changes of hold than when a bridle is ufed without a
chain, becauſe the bridle may be made
longer from the bole, without any dan-
ger of breaking, being ſupported by the chain. The parc of the beam alſo be- tween the bridle and ſtaple is ſomewhat fecured from breaking upwards; and if the ſtaple could be conveniently placed at the very ſtile, it would be fill more ſecure. This‘bridle is made with notches on eâch fide of the middle, in order to give‘the plough more or leſs
nd.
When

es hag
3!lons
Bathis-
Ì ¡ee E bles >[0h ut 4 Inade [Dln-
1 Þr the
FS) e
Ecyvhat ¿ ¿ndit @llaced \Linore 9! with H, in y leds
Vhen
Of the Uſe of the Chain: TL When two horſes go” a-breafſt,‘the draught line falls in with the diredion of the plough, or is right alongthe beam. But when thé lhiorſes go‘all in the furrow, the draught line is then re:
moved to thé right, ſomething more than
ECA
12lf‘the breadth of the furrow,(ſee fig. 25.) where A DB repreſents the draught line, when the horſes are all in the furrow, and À EC is the drau ght line when the horſes arc a-breaſt. D is the point where the line A D B falls in with the furrow, and A is the point where it falls in with the centre draught. DE will then be‘the diſtance of the notch of the bridle, upon which the
chain ſhould be placed, from the other
draught line AEC. It may be obſerv-
‘ed of this manner of drawing, that the
draught

ió Of meUſe of the Chain:
draught line can never fall parallel with
the direction of the plough. Indeed, even wliere the horſes are a-breaſt, the draught line is not exaûly in the di- reâtion of che plough, becauſe the land horſe generally keeps more than nine
inches from the edge of the furrow.*
Of the Uſe of Wheels to a Plough.
From the deſcription which has al- ready been given of the various parts of a piough, and the reaſons which have been offered for giving to each of them the form which I have recommended, the reader willi ſee what part of the work 1s performed by each, and will be able
to judge of any alteration‘which may
_
N
be propoſed by way of improvement,
Fu hether

| al with|
deed,| N, the|. he di B: land T1 nine
WV, Ve
18 A D; parts Ln have (them qnded, 4 work
: able | may nent,
Z ether
v1
Of the Uſe of Wheels. 152 whether or not they tend to make a plough perform better work, be more ca- fily drawn,more regular in the draught, or more eahily managed. Care has been taken of each of theſe things in the for- going conſtructions, and experience ſhows that a plough may be ſ made, as that, when working in even and well dreſſed ground, the plough will per- form the work almoſt of itſelf, requir- ing very little attention from the ploughman.
But ploughs have been uſed which are of a very different conſtruction, having many parts which are not in the plain plough, the ſubje( of the forego- ing ſheets. As theſe ploughs are now in great vogue, and much uſed both in
England and other countries, and as U the

F 54‘Of thè Uſe of Wheels
the parts added are intended for pro-
ducing ſome of the good efleéts juſt now méntioned, it will be improper to pafs them over without notice in this treatiſe. The chief of theſe propoſed improvements is the addition of wheels to’ a plough, which fhall therefore be particularly conſidered in this place.
E has been a very general opinion, that the addition of wheels is an im-
provement of the plough, but artiſts
have differed exceedingly, both as ts-
the manner of applying them, and the parts to which they ſhould be applied. Since theſe parts are only ſubſervient to the part of the plough which really per- forms the work, and as the manner cf acting of a wheeled plough differs con-
ſiderably from that of a plough without
wheels
BU rr

nion, _1m-
ENG
(4s LO
1d the plied, ent to PEE er cf coN- hout
heels
Of the Uſe of Wheels. 155 wheels, we muſt conſider particularly their action, at the different parts to wluch they may be applied, in order to judge of their advantages or diſadvan-
tages. The reader alſo wil eafily fœe,
that the form of that part of the plough
which is in the ground, and really per- forming the work, muſt be regulated by the ſame principles in both cafes, and that what is moſt proper for the one wil alſo be moſt proper for the othèr.
One manner in which wheels have been uſed, is to have two wheels appli- ed to the beam, by a carriage, Wheels applied in this manner have their prin- cipal efe in regulating the plough, by giving it a certain quantity. of furrow, œitherin breadth or depth. While one
Leg; wheel

156 Of the Uſe of Wheels.
wheel continues in the furrow, and the
plough is ſet to take any gwen breadch, it muſt keep that breadth very regular- Iy, and not be liable to make any ſud- den bend, and is therefore very proper for keeping ground ſtraight that is al- ready laid out in ſtraight ridges. Alſo, when the beam is fixed to any height of
the wheel carriage, the plough muſt be
kept at a fixed depth, and, by ſhifting«
the beam higher or lower, the plough may be made to go deeper or ſhallower, as occaſion may require. When, there- fore, the ſoil is egually deep, and free from obſtacles of ſtones or roots, this plough muſt require little labour in
managing it.
Bitt,

d the adth, ular- ſud- roper 18 dle Alſo, ht of iſt be INS 4 \v0gh lower, there- d free , this
1x N
Bitt,
k 1}
Of the Uſe of Wheels. I 57 But, on the other hand, when the ſur- face is hot a pláne,t either level-or‘ins clined, but has à number of heights and hollows, as is freguently the caſe, eſpecially in croſs ploughing, the wheel- ed: plough cannot be ſo proper as the one without wheels, which the plough- man can regulate to his mind, whereas the wheeled plough is out of his power. In like manner, when the ſoil is not e- gually deep in the length of a furrow, or would require to be ploughed to dif- ferent depths at diferent places, it can- not be proper to have the plough fixed to one certain depth. Itis known that, in general, the crown of the ridge will admit of being deeper ploughed than what is near the furrow,
Te

758 Of rhe Uſe of Wheels.
I€ muſt alſo be obſerved, that in mak-
ing the firſt furrow of the ridge, the wheel which, at all other times, goes in the furrow, muſt now be as high before the furrow 1s made, as the one on the unploughed ground. This requires the plough to be altered every time we make the firſt furrow of a ridge. On thie other hand, when a plough is mak- ing the laſt furrow of a ridge, the wheel, which, at all other times, goes on the unploughed land, is now in the furrow of the former ploughed ridge, or on the oppoſite ſide of the ſame ridge. This will, in like manner, require an alteration of the plough.
From theſe obſervations, it appears that inconveniencies ariſe from keeping
the plough in one uniform depth, and
that
Fr
FT = 3

n mak,
O, the|
L065 IN Qtfore hn the rés the E ne Me a On 1 mak- rheel, en Me géurrow D'or 0 4 ridge,
dire all
pears
jeping
4, and
what|
Of the Uſe of Whéete 159 that by the freguent alterations here ipecifed, very little labour is ſaved to the ploughman upon the whole. It muſt alſo be obſerved, that the part of the wheeled plough in the furrow muſt be the ſame as that of the plain plough, when the centre draught is the ſame. Buc, in this plough, the draught line has often two different aſcents, one rom the part of the plough ading in the furrow, to the wheel carriage, and the other from the carriage to the cattle. To this is added the draught of the wheels and carriage.
In finding the draught line of this plough, we muſt conſider the parts upon which the preſſures are exerted. With reſpeé to the part of the plough which ïs in the furrow, the preffure is exerted
011

169 Of the Uſe of Wheels.
on thât point which we have called the centre of aQion. This will vary alittle, by a change in the depth of the far- row, and by any difference in the length and poſition of the ſock and coulter. But, in general, when the&dif tance between the point of the ſock and the heel is two feet nine inches, the draught line will inter the ſole about 14 inches back from the point of the ſock.
With reſpect to the carriage, the preſſure of the draught is always exert ed on that point to which the draught is applied. Some may think, that the preſſure of the work is exerted on that point where the beam reſts upon the carriage. But, in whatever way the
e draws the plough, or beam, or
10
| TEA 6 | Una dl,

led the
1 little,
è fUr
In the
Kk and the diſ. e hock les, clie 1: about
of the
l'e, the 18 EKErt- aught
nat tle
on that
von the
¡ay the
am, 01
11
Of rhe Uſe of W heels. IÓLI in whatever way the carriage is made, it has all one effe, and the draught line will never follow any elevation of the beam, nor the various turnings of the diferent parts which connect the centre of action with the part of the carriage to which the draught of the horſes is immediately applied, but makes a ſtraight line through them all. Thus, then, there are two aſcents of draught, one from the centre of aQion to the draught point of the carriage, and the other from thence to the horſes. If theſe two aſcents make but one ſtraight line, the plough will, in this reſpec, differ very: little from the plough without wheels, becauſe then there is no preſſure upon the wheels, It is true, that the plough will not go
ZA dee per

E
PY) y/ Po og: ay 7 2 REZA AA' BRI SMI PR= A5 TLOZ Of the[SG Ile OP PP 12 CCLS&
deeper, but it will be. eaſ
. LY= ES Tf the firft aſcent of draus
Taie% EE; DE IS OTECaTtCl )) C25
than theſecond}; ſo: as that‘they make
below, at the part ofthe car-
an“angle riage which is drawn by, there will then be a preflure upon the wheels, and thé plough will be regulated in its depth,s and will go- ſteady."Fhis preflure upon the wheels will be ſo much the greater, as the two’ aſcents of draught differ more from each other.
It is thought that power is gained by thus raiſing the line of draught upon the carriage, becauſe, in the common way, the draught is partly employedin pulling the plough out of the ground, and the remaindér only is employed in pullinè the plough forwards. In the
ated. pPloue,(he drAught of thé
cattle

Tand thé | depthy be upon breater,
1: differ
uned by hit upon (cCommo! loyed1i round, loyed in| In the
of the
cattle
Of the Uſe of Wheels. 1bg cattle may be made parallel wich the HDLottom of the furrow; but it muſt be here o»ſerved, that by giving this di- rection to the draught of the horſes, we increaſe the preſſure of the wheels; and while power is gained by leſſening the
„aſcent of draught, power 1s alſo loſt by increaſing the preſſure upon the wheels. I amof opinion, that,when theſe circum- ſtances are duly attended to, and when we conſider the uneven and compreſ- ſible ſurface upon which the wheels muſt move, we ſhall find that no power will be gained by placing the draught higher upon the carriage than the fſträight line which joins the centre of action of the plough with the height of draught, as it comes from the lower end of the horſes backband. With. reſpect,
there-

104 Of the Uſe of Wheels.
therefore, to the ealine( of draught, the
wheeled plough does not ſeem to poſleſs any âdvantages, and it is loaded with the additional weight of the carriage and wheels.
There is a wheeled plough of a much more artificial conſtruction than the one now deſcribed, having wheels or rollers applied to that part of it which is in the furrow«
In order that the furrow ſde of a vlouch may ſhift and turn the earth in the manner deſired,' the plough muſt be ſupported againſt the reſiſtance which it meets with from the earth. As the earth is raiſed and preſled to the right, the plough is preſſed downwards, and
to the left, and muſt be ſupported by
the bottom of the furrow, and by the
firm

1 els or
1 which
eof a earth in cmuſt be [e which | As the e right, ds, and rted by by the
rm
Of the Uſe of Wheels. 165 firm ground to the left. The ſole and land ſide of the plough are therefore ſtrongly preſſed, and expoſed ta great {riction, in the ſame manner as the ſole of a ſledge drawn along a ſoft road. In the plough now under conſideration, a wheel has been ſubſtituted in place of
the ſole, and another wheel, or rather
roller, with a perpendicular axle and
horizontal motion, has been ſubſtituted in place of the land ſide. This plough differing from a common plough in the ſame manner‘as a wheeled carriage differs fram a fſledge, it has been called a carriage plough, while the common ploughs are called ſledge ploughs. It is alſo commonly known by the name of Moore’s patent plough. As theſe wheels are placed in the moſt proper
manner

166 Of the Uſe of Wheels.
manner for producing the effect that
is deſired, this plough is very fit for en- abling us to judge of’ che value of this
improvement. The improvement is
ſuppoſed to be the ſame upon the plouglh
that wheels are ſuppoſed to be upon a ledge. The ſuperiority of the wheel-
carriage above the ſledge is well known.
Now it is thought, that as the wheel,
which, in this plough, performs the of- fice of the ſole, is I6 inches in diame- ter, while its gudgeon is but one inch, the reſiſtance to the plough’s motion ariſing from the friction of the ſole is diminiſhed 16 times,
Granting this, the improvement is not ſo great as is commonly imagined. For a wheel of 16 inches diameter cannot be
placed ſo near the point of the ſock, as
ta

_- -
Dt that Yr en- If this Lt js Souoh
R Don 4
Sr heel.
down,
neel,
| of- AMe- 3 1nch, 1otion
«ole 15
AA TP PTIZ1 1 BS Of the Uſe 07 it heels, 7 Ó
SJ
tofperſorm the*oflice! ofthe ſole. Tc only performs the office of the héel of a plough. Now, we have ſeen, that the preſſure upon the heel of a plough, and conſequently its friction, is not conſider- able, if the plough is conſtructed accord- ing to good principles, being nothing more than what is neceſſary for making the plough ſteady in its motion. In Moore?s patent plough, the preíſure of the heel may be reduced‘to nothing, becauſe it has wheels under the beam. But in the way in which it is common- ly made, the preſlure at the heel is very conſiderable, and the friétion may be greatly diminiſhed by means of the wheel at the heel of the plough. This advan- tage however is much more than balan-
ced by other inconveniencies, The
ſole

168 OA the Uſe of Wheels.
ſole of a common plough being made
ſmooth and even, and in the direcion of the plough’s motion, it ſuffers no re- fſiſtance, but what ariſes from friétion alone. Prefling upon the furrow with its whole furfáce, no part of it cañ ſink deeper than another. Ic is alſo wel known, that its friion is the ſame whe- ther its whole furfäce is preſling, or on- ly ſome parts of it. By experiments which I have made with great care, I have reaſon to conclude, that the fric- tion of a plough ſole does not much ex- ceedthe fourth partof the preſſure which is aCing on it. I have alſo made expe- riments with a wheel placed in the man- ner of Mr Moore’s. I have found its reſiſtance to be very irregular,&ccord-
ing as the ſoil was uniform ar not. A
wheel
&
>
re ENEE

L made Dion 110 res ſion D with
n fink 6) pel] li w'he- or on- ments Ee, L F? fric- ch ex- ¡which [ CXDE- | man- 1d its cord- EA
wheel
Of thè Uſe of Wheels 169 wheel of 16 inches diameter reguires near# oí its weight or preſſure to draw it over an obſtacle one inch high, and near one half of its weight to draw it over an obſtacle two inches high. Many fuch obſtacles occur in the bottom of a furrow, fromhollows, eminencies, ſtones, ſofr places, and looſe mould, which tum- bles in, and it would be but a moderate eſtimation to reckon them equivalent to an obítacle of two inches high. The reſiſtance therefore to ſuch a wheel is nearly double the reſiſtance to a com- mon ſole plate. I do not by this mean. to aſlert, that the reſiſtance to Moore”’s plough is double of that of a common pltough, becauſe I have obſerved already that the reſiſtance at the heel is but a
»
mall part pf the*whole reliſtance to %.
D which
Futa

70 Of the Uſe of Wheels.
y y PA re CEL1 CHES
pond D
this refiſtance alone upon wh wheel makes any change-
I will now add, that ung of this wheel in place of a common ſole, great- ly hurts that ſteadineſs of motion, which we have been at ſo much pains to pro- eure, and which is one of the greateſt properties of a plough. For, as the wheel ſinks into a hollow, or goes over an eminence, the point of the ſock muſt be raiſed’ or depreſſed. Accordingly it 7s found, that when it is uſed without a carriage under the beam, the plough. goes with a very hobbling motion, and: although the beam-carriage prevents this in Mr Moore?s plough, it muſt be' acknowledged, that the labour of the
cattle muſt be increaſed.on this account.
TWWicly

| Of the Uſe of Wheels. 174
With reſped& to the wheel which per-
hh th Forms the office of the land ſide, the [ ¿ſame inconveniencies muſt attend it in E this| a greater degree, becauſe, from its ſitu- C great-| ation, ic cannot be above nine inches D, wich P diameter. Indeed, it-cannot be nearly 10 pro- ſo big, without projecting too much to Jreateſt the right: ict is, therefore, much more lus the affected by any inequality-of ſurface )'s Over than the other wheel. The bad efes è\: ml of theſe inequalities are more conſider- Cinoly it able on this wheel, for this additional vithout reaſon, that the wheel itſelf is placed in | plougl a part of the plough where there is (n, and really a greater prefſure. „events A plough of this conſtruGion, but hult be| without wheels under the beam, has Cr been tried in company witch other count.| ploughs of the common form, and it
| Na
Wid| Ed

172 Of the Uſe of Wheels.
was found to r'equiré“at leaſt a third
more power to draw it. I did not, how- ever, attribute the whole of this to the wheels, becauſe the plough was defec-
tive in the conſtruction cf its other
Thiere is“another wheeled plough which deſerves to be taken notice‘of, becauſe it has met with the approbation
ofthe ſociety in London, for the encou-
- ragement of arts and manufactures, and
has a very great name, as the plough
which is drawn by the leaſt force poſ-
ſible.‘The make of the body of this
plough is not very different from that of the Rotherham pÞplough, from the point of the coulter and the ſock back- wards. Tt differs a little in the manner
of framing, the left ftilt being extend-
ed

third
)| how.
No the|
Slefec-
È other
blough Le of, ation ncou-
js, and
ne pol of this 1 that
n the
back-|
anner
tend-
ed|
Of rhe Uſe of Wheels. 178 ed forward, ſo as to ſerve in place of the ſheath. The mouldboard alfo is ſo contrived, that it may be ſet at different widths.
This plough has three wheels. One fthem is placed under the fore end of the beam, which has a bend upwards at ile place of the coulter, on purpoſe to give room for a wheel of two feet three inches. high. The other two wheels are on an axle-tree fixed tothe beam, a little behind the point of the coulter and ſock. One of theſe wheels treads upon the unploughed ground, The o- ther is let down by means of a crank upon the axle, ſo as to go at the bot- tom of the furrow on the right fide. TFhe third wheel is fixed to the beam by a frame, which comes back as far as the
point

[74 Of the Uſe of IV beels,
point of the coulter, where it is fixed to
the beam. A parc of the frame comes perpendicularly up from the centre of the wheel, and goes through the beam like a ſlider, ſo that it can be ſet at dif- ferent heights. By this means the plough is tempered to any particular depth, Thus the plough becomes a ſort of wheel carriage.:
The view of the ſociety in making ex- periments with this plough, was to diſ- cover whether the whole amount of friction on a well conſtru@ted plough was an inconvenience which was worth regarding. The reſult of the experi- ments was, that it was not. The reſult could not be otherwiſe; for blé eflect of
theſe wheels was little more than carry-
ing the weight of the plough itſelf, One

20 Vſ- pint of
ough £vorth perl
ceſult
of
Parry [tſelf, One
T{5
Of the U
le of Wheels.(75 One of the wheels, indeed, as a little like the wheel in the ſole of Mr Moore?s plough, and has all its inconveniencies. This diſpoſition of the wheels is at- tended with other great inconvenien=- cies, As two of the wheels are very near the point of the coulter and ſock, whenever both, or one of them, are raiſed upon any eminence, the point of the plough muſt immediately riſe, and the conneding parts are expoſed to very great ſtrains, When the wheels have got over the eminence, and would come down again, they are prevented, be- cauſe the ſock is now at a leſs depth than before, and muſt advance ſome ſpace before it can regain its former depth. By this means the wheels are often kept from prefling on the furface,
Yy hule

ï76 Of the Uſe of Wb.
while, at othér times, they are moſt vî-
olendlyſqudzedtto it; Mosthat the plough is neither regular in its depth, nor in the labour whicli it gives to the horſes, unleſs the ground be a ſmooth plane. Even in this cafe, the labour of the cattle is conſiderably increaſed, be- cauſe the two wheels, being ſo near the coulter and ſock, are violently ſqueez- ed into the ground. By thus ſinking into the ſoft earth, théy reguire a force to draw them forward, nearly equal to what would draw them over an obítacle half as high as the depth to which they ſink.
I have given this account of the wheeled plough, in order to ſhow, that
beſides the other inconveniencies to
which they are expoſed, they are not
=> Ta
= CD, = as
EEE >. =—

Of rhe Uf/e of Wheels T7A adapted for procuring the very advan- tages«for which they are intended. The advantages alſo are but inconfſider- able, and by no means equivalent to the great additional expence, to the riſque of going out of repair, and the trouble of keeping them in order. I might have faid, that they poſſeſs no ad- vantages over the ſledge plough; for they cannot be uſed except in well dreſ- ſed ground, free from ſtones. In ſuch ſoils, there is no uſe for them; for it ap- pears that the principles upon which a plough operates, while it is performing
its work in the manner reguired by the
farmer, are ſo certain, that a plough
may be made which will perform the work with hardly any attention on the part‘of the“ ploughman. Whether I
2 have

N GZ Vv E R SE APEL
E E—————_——— 2
EEE LS
i798 Of the Uſe of Wheels.
have ſucceeded in giving a conſtruction
of a plough which is perfe in this re- fpedct,. the reader muſt judge, or expe- yience ruſt determine. The intelligent reader muſt ſee that the thing is poſ- fible; and if ever it is done, the ploúgh conſtructed in: this manner muſt be pre- ferable to-all others, for cheapneſs, fim- plicity, eaſinels of being kepet in repair, and its capableneſs- of being adapted in an inſtant to every change of ſoil which the ploughman can obſerve.
Here follows the deſcription of 2 plough which can turn the furrow to either ſide at pleaſure, and is therefore uſeful for ploughing along the ſides of ſteep hills, where the furrow muſt al- vays be turned tothe lower ſide.- See
—
foe oa Nos Te ar alf.
No. Ee

Of turning the furrow 10 cither fide. 179
No. I. is a view of the frame part of
G8 N the plough before the mouldboard is Oxpe-(y put on. The redd or curve of the beam Iene cannot be leſs than is repreſented in the 2 poſ figure, otherwiſe tt would not leave ‘ouh room from the motion ef the coulter, do pre which is all below it, as is repreſented R in fig. 2. A much greater curve is Ävair, hurtful, by reaſon of the weight of the BE plough being too high, becauſe this Eh plough muſt always be leaning confi- derably to the land fide. Rens The ſtilts may be made in four difte- E i rent ways. I/. A half length of a ſtile up may be framed to the beam, and fixed itt to the ſheath and head, and the whole 1 al-| kept together by a bolt EF, as is repre- bisee ſented in No. 1. To the part above
the beam, two handles may be fixed by
three

180 Of turning the furrow to either ſide.
three rungs.“2ály, A piece of‘wood may be taken, which has a caſt to the left hand, ſo that it wHl anſwer for the left handle, GERE framed to the beam, as already mentioned. To this may be ſpliced a handle of an equal caſt to the oppoſite fide. zdly, M PIECE of wood may be formed which has a natural fork, ſuited to this purpoſe.
<hly, A piece of wood may be taken which has a proper caſt for a fſtilt up and down, and of ſuch toughnefſs, that when it is fawn along the middle, near to the beam mortiſe, it will bear to be bent aſide to the neceſſary width.
The ſheath is about If inch thick by five inches broad. The head is three inches deep, by four inches broad. In
framing of theſe parts together, they
are
E E R A A CRIÉ O E a

ide, Cv ood ) the Pr the | the \ this equal : piece 914s 2 Moſe, Inken up 5, that Î| near < to be
4
2)
[k by
hree
Of turning the furrow to cither fide. 18x are all placed in the direQion of a line along the middle of the head and beam.
The lefr mouldboard is ſeen fide- ways in No. 2. Q R being the fore edge, where the two mouldboards meet, and S-Tis fhebindérmoſt edoe. y The two mouldboards are ſcen from above in No. 3. which ſhows the angle which their upper edges make with each other. The fore edge of the mouldboard is alſo ſeen in No. 1. being repreſented by the dotted line GH. Theſe mouldboards are mitred together before. The inſide of the mitre is repreſented by K Lin No. 1. They turn round an iron bolt DC No. 1. which goes through the beam and head. The bolt has a head at C, which is ſunk into the head of the
plou gh

x82 Of turning the furrow zo either ſide.
plough, and ict is ſcrewed at D, where there is a nut. This bolt paſſes through the ſolid wood of the mouldboard, through the mitre: therefore, before the mouldboards are faſtened together, a half round grove is made in each, and when they are joined, theſe groves make a round hole, as if made by an
augre. The angle which the under-
fide of the mouldboard makes with the
upper fide, 1s about 18 degrees, both being ſtraight, ſee Nas: 6. where A C is the lower edge of the right hand mould- board, and A B its upper fide, The
mouldboards may be formed to the re-
gular twiſt, by means of the bevel, fig.
17. The angle between them at the
le ſhould be the ſame with that made
by the land ſide and mouldboard ſole
a
OÏ

a
LZ
“ude;
= Where
Ì‘01 oh
bard, «fore Ather, S1), and Stoves by an ander- 7h the 5 both mA C is Eiould- Y The he re: «dl, fg, nt the [made d ole
A
ol
Of turning the furrow to either ſide. 182 of 2 common plough, which is about 15 degrees. Then the mouldboards will make an angle of about x 5 degrees below, and 52 degrees above. In order to keep them at their proper angle, and to ſtrengthen them againſt the prefure of the earth, which tends to force them together, they are ſecured below by a torked frap of iron of the proper angle, which has a hole through it for the mouldboard bolt D C No. r. to paſs through. This ftrap is miled to the lower edge or ſole of the mouldboards, They may alſo be ſecured by a rung between them, ſo placed as to paſs free
between the ſheath and ſtilt. They are
, fecured above by what EF call the iron
beam, repreſented ſeparately in No. 5, and ſeen ſideways at E QT, No. 2. This

184 Of turuing the furrow to either ſides This beam, No. 5. is formed to the | proper angle E A F of 5r1 degrees, and WM has a hole at G, through which the up- I| per part of the mouldboard bolt paſles. I The part À N projets forward, right with the middle of the angle EAF, M formed by its ſides, and has a ſquare
mortiſe at H, for receiving the upper
] | | | | Ï || part of the coulter, as is more diſtinäly || feen in No. 2. The.fore part N of this M iron beam is formed into a point, for | N being received into the catch FE of |' N, No. 2. This iron beam between the. | h coulter hole and the point of the mould- boards is two inches thick, and the end
| M of the coulter which goes into the hole H is two inches by 3
There is alſo fixed on the upper edge
M of the mouldboards behind, an arch of
iron
(ji
¡ro! thei ſcdl&! 1A reſ 3): TO nB
| andTS|

Ilpper nly M chis Dit,(or
E of n the =10uld- Y e end € hole [ eÂge ¡ech of
iron
Of turning the furrow to either ſide, 185 irh, repreſented; by E M, Nos 24 TÀ the middle of wiuch; at Kz, ¿there is a ſocket, for receiving the handle KTN;
AB Crof-Nori2 ande E Eof+Noss repreſent-the. catch. which Keeps...the mouldboards in their proper poſition. This catch goes over the beam like an arch, and has a bolt DE through it, and through the beam, round which it turns upward and downward. The holes at A and C are for receiving the point of the iron beam, repreſented by Ein No: 2. andby Nin No. 5: ¿Fhe catch is made very ſtrong between theſe two holes and the bolt holes D and E No. 1.‘namely, about 2 ſquare.- The catch is made to keep its hold of the 1ron beam by means of a long ſpring, repreſented by C D in No. 2. and by
Aa ED

756 Of turning the furrow to either fide,
F Bin No. 3. Its fore part 1s mailed to the beam; and as the ſpring acts up- wards, it preſſes the arch of the catch upwards, and’this Keeps the hole A or C on the point of the iron beam. This catch is lóoſened fromits hold by means of a ſtring or rope, which is faſtened to the top of tlie arch F, No. 2. and’ comes
backward, through a ſtaple M on: the
beam, to’‘the part L of the jointed"
handle. By raifing« the end of the handle, the rope is drawn tight, and it
pulls down the top of the arch of the
catch, by which the other end E of the
catch is drawn of from the point of the
iron beam. The mouldboard being;
now ſhifted to either ſide, by puſhing
the handle to the oppoſite fide, the rope
îs then allowed to ſlacken, and the 0=-
ther

ſomes hr the “inted 4 he Zand ic rh the
ofthe‘
got the
y being
ſhin?
Of turning the furrow 10 either fide. t87
ther hole of the catch immediately falls
:on the point of the iron beam, and
keeps it faſt.
In order that theſe. mouldboards may
be able to.ſhift to the proper angle, it is
neceflary-that the‘lower part of the
tilt, and the heel-piece at B, No I. be
reduced to the thickneſs of the ſheath,
In order.to make this more effe@ual,
and alſo to give that mouldbeard, which 1s at.the firm ground, ſome ſupport {rom the head of the plough, the upper
ſide of the Lead is ſloped of for an inch
down, as is repreſented by the line AB,
No. 1, The lower edge of the mould-
board is egually ſloped of on the inſide,
ſo that when the plough is ſet, the land
fide mouldboard claps cloſe with its
chamfered edge to the chamfer of the
UDPEr

188 Of turning the furrow to cither ſide.
upper fide of the head, and is then ſup- ported by it, and all dirt or ſmall ſtones
s by this means prevented from get-
jad D
ting between them, andthe mould- board and head make one uniform ſur- face, without any projection on that fide for about ſix inches up.
The edge of the coulter muſt be ſet right in the middle of its thickneſs, but the back of the coulter muſt have a thickneſs equal to# of its breadth. By this means, when the mouldboard 1s ſhifted to one ſide, that face of the coul- ter which is next the firm ground, will be fluſh with that ſide of the head, or will lie in the dire@ion in which the plough is going, agreeable to the prin-
ciples formerly laid down.
The

Nhe ſct Á, but Ive 4 E, By Jard 1s J coul- E 1, will Ad, or Fh the [; prin-
The
|
|
Of turning the furrow to cither ſide. 189
The lower part R, No. 2. of the fore edge of the mouldboard muſt always be kept cloſe to the upper fide of-the ſock. If it projets to either ſide, and a ſtone gets into the angle, the plough will be broken, or its motion will be prodigiouſly- retarded:- therefore, the upper fide ofthe ſock muft be made of a breadth proportioned to the ſhift of the mouldboard, at the place where the lower point of the mouldboard traverſes over it. This is repreſented in No. 4. where D is the centre of the motion of the mouldboards, and A is the fore point of them when the plough is turn- ing the furrow to the left hand, and F' is the place of it when the plough turns the furrow to the right hand. The breadth of the ſock A F will therefore
depend

e rauer Brann e R
=
SR E rg E E
e
7:90 Of turning the fürrow to either fide.
depend on the width of the ſhift of the plough, and on dé diſtance from the bolt D. In the dimenſions repreſented in the figures, A F muſt be four inches, becauſe the point of the mouldboard ſhifts two inches on each ſide of the middle line of the plough.
If the bolt, reund which the mould-
boards turn, were placed perpendicu-
lar, as at I C, No. zx. the upper ſurface of the ſock, No. 4. ſhould be quite flat. But when the bole D C, No. z. leans back above, the upper ſurface of the ſock between A and F, and behind it a little, muſt be rounded a little a- bove. Thus the point of the mould- boards will keep cloſe to the back of the
ſock as the plough ſhifts.
While|

R y Se,
Of turning the furrow to either ſide. to
Wi While the point A, No. 4. ſhifts over N to F 4 inches, the point G of the coul Tnted ter ſhifts over to H 6 inches, ſo that in fta, both poſitions of the plough, it is an inch Paard without the point of the mouldboard, Tte and better than half an inch withouë the land ſide of the head, which is æ
tL uld- very proper pofition. If the fore edge Alicu- of the coulter is parallel to the bolt D C, L'face the upper end of the coulter will ſhiſt as O: fat muchas the lower. Ff the edge of the E leans coulter and bole are narrower above + the than below, which is the caſe in the nd it figures, the upper end of the coulter Ile a- will hift leſs. This ſhift of the upper - ould-| end of the coulter is repreſented in No. Efe| 5. where the line MG N is the middle | line of che plough,.T is the upper end
Vile| of the coulter, when the plough turns
the

i E SASE:
> 5 Tae
t92 Of turing the furrow to either ſide.
the furrow to the left hand, and K 1s its place when the plough is turning the faurrow to the right. This ſhift in the figures is 27 inches on each ſide of the middle line, or 5 inches in all. At the ſame time, the upper point A of the fore edge- of the mouldboard ſhifts 3 inches from À to L. This ſhifting of the upper and under parts both of the coulter and of the mouldboard edge der pends, as has been already ſaid, on the poſition of the bolt D C, and on the diſ- tance of theſe parts of the coulter and mouldboard from the correſponding parts of the bolt. Attention mult be paid to theſe circumſtances, in order that they may have always a proper po- ſition. The ſhifting of the fore point of the iron beam muſt regulate the diſ-
tance

S At F ofthe
Mhifts 3
Mh 9 of
M thè bae de» Ln(he 1e dil- [1r and Anding zill be [1 order er PpO- [( point € dil-
tancc
Of turning the furrow ro either ſide. 193 tance between the two holes of the catch.
It is neceſlary in this plough, that the horſes go all in the furrow. For, in ploughing along the ſide of a ſteep hill, a horſe cannot find footing on the un- ploughed land, but will be always ſli- ding into the furrow.
This circumſtance requires a bridle of a particular conſtruction, to allow the draught to be ſhifted at every turn- ing of the plough. See No. 3.
QP is the bridl&, 10 inches within from Q to P. It is ſtraight before, and without any notches. The horſe tree has a ring, which ſlides from fide to ſide on the bridle. At Q and P are two rollers or ſheaves. A rope has its mid- dle fixed to the ſliding ring, and the two ends are made to paſs through the
B b relier

104 Of turning the furrow to either ſide.
roller Q and P, and the two ſtaples oñ thé upper ſide of the beam, juſt before the catch bott DE, and through ano- ther ſtaple in the ftilc G, juſt by the beam mortile. They then are made to paſs through two other rollers on the upper fide of the ftilc handles at R and 5, and then their ends are brought to
gether, drawn tight, and tied togêther.
From this deſcription of the ploughz
Ls it 1s eaſy to ſee, without repeating what has been already ſaid, how all the parts are ſhifted.
Figures 7 8 and 9 repreſent tlie parts of another ſhifting plough, which has been a good deal employed. PM, fig. 7. 1s a lide view of the beam, A C D is the bridle, having holes in its fore paté, for giving more or leſs hold. The bri-
dle

\ he, les oh before zl ano-
y the
1j what
È° parts
I? parts
[h has I, fig, D's par, 2 bri-
dle
Of turning the furrow to either fide. 195 dle turns in a bole BC, which paſſes down through the beam. The tail C D comes a good way back, and has, on ts Upper fide at D, a pin with a broad head, which takes hold of the end H of the iron beam H I L, which turns on a bolt K L, in the ſame manner with the ¡ron beam of the other ſhifting plough.
A catch bolt G H goes down through the beam at G, and ſerves to fix the 1ron beam to the wooden beam, when the plough is ſhifted. This bolt is kept down by a ſpring FG. It is drawn up by G RN, which turns round a joint at R, and has a rope reaching from N to the ploughman’s hand. When he pulls the rope N O, the point G of the catch riſes, and raiſes the ſpring and bolt GH, and looſens the iron beam
from the wooden beam, Fig,

196 Of turning the furrow to cither ſide. Pig. 85s a view öf the upper ſide
of the ſame parts, CED is the bridle,
‘turning on the bolt at EL. MFG is
the iron beam, turning on the bolt at G. Tn the fore part of this iron beam at D, there is a hole for receiving the broad headed pin, which is in the tail of the bridle at D. This hole 1s made oblong, to allow the pin to ſhift along ît as the plough is ſhifted. The part L M is formed into the arch of a circle, of which the centre is G, and it has a2 hole at each extremity L and M for re- celving the catch bolt. It has alſo a hole in the middle between L and M for the ſame purpoſe. In order to keep the arch L M cloſe to the beam, ſo that the bolt G H, No. 7. may fall truly in-
to the holes in the arch which are made
to

“ude, 1 fide ridle, UG js dit at Qeam 710 the e tall i n2de Ulong N] part Zire,
has 4
Nor re
alo ga
1d M ' keep that y in- nade
{0
Of turuing the furrow to either fide. 19 to receive it, there is a ſupport for the iron beam,‘repréſentéed in ig. 9. BDC is this piece, The part B D goes thro? the beam, and 1s ſcrewed or rivetted a- bove at B. A tail fticks out at H, which is nailed to the under fide of the beam. It paſſes thro? between the arch L M of ſig. 8. and the arms. The part DC pro- jeâs forward below the arch, and it has a hole at C, exadly below the hole thro? the beam, throngh which the catch bolt comes. When, therefore, the catch bole has been drawn up, and the arch L M comes into ſuch a poſition, that any of its holes comes exaQly between the hole in the beam and the hole in the piece B D C, the catch bolt being let down, it goes through all the three holes, and Keeps all faſt together. Whenthe plough
throws

LLL
SG Aie Ema dti©
— per
EE SEE EPE ELE ZEE
E E EE EEE ESS
a E
198 0f turning the furrow to either ſide.
throws the furrow to the left, the catch bolt is in the hole at N, and when ic throws the furrow to the right, it 1s 1n the hole at L. The plough may alſo be employed to throw the furrow both ways, by putting the catch bolt into the middle hole of the arch LM.
The iron beam cannot ſhift any more than the open ſpace which is within the arch L M, becauſe, when ict is put ſo much to one fide, it is ſtopped from going farther by che pin BD of No. 9. ítriking againſt one of the arms,
The hind part of this iron beam has got two tails, in the ſame manner as in the other ſhifting plough, by which it is
fixed to the mouldboards, and all the
other parts are made in the ſame man-
NECF
Of
Hat, m |———

“
[199]
L Of Wheels in general;
To attempt to prove that a carriagé 1s inore eaſily drawn upon wheels than upon ſledges, would be an affront tó the underſtanding of the reader.
But whether high or low wheels are fitteſt for the purpoſe has been a ſub- je& of diſpute, even among perſons of kill. Reaſon and experience, however, ſeem perfeâly to agree in this, that wheels, whoſe centres are on a level with the moving power, will be caſieſt drawn along a level plane, and that the higher a wheel 1s, It will more eaſily set over any obſtacle, if the moving power 1s not below its centre. It ſcems
CO

200 Of Wheels in general.
to follow therefore, that carriages drawn by horſes or oxen fliould have wheels wlioſe centres havé the Height of the draught line, that is, of the ſhoulders of the horſes, or the yokes of the oxen.. This is true, however, only in the caſe'of a horizontal road. In going up a bill, the diſtance of the line of draught from the road is ſomewhat les, becauſe, when a man, or any other animal, is ſtanding upon the fide of a ſlope, his height is inclined to the ſlope, although it is perpendicular to the hori- zon. As this is the ſituation in which it is of the greateſt importance to dimi- niſh the labour of the cattle, it follows, that the height of a wheels centre ſhould be ſomewhat leſs than the height
of the line of draught. But what the
D Dd 1a fp= 1 it à SRS= GLIICLENCC
Oi 14
1:

> 1ages D have Bigli: Ì the Ee of N, only D,[n I line IC what fother D: of a
I ſlope,
+ hort|
which «dimr -llows, centré eight at the
Þ ARA LPT L rend
Of Wheels in general. 20k. difference ſhould be depends upon‘a great number of circumſtances, which thoſe who make uſe of wheel carriages ſhould be beſt acquainted with, Four feet eight inches is reckoned a very g'dod height for a cart wheel, and has been thought preferable to any other. But the great loads which are drawn in the coal carts at Glaſgow, which go upon wheels above ſix feet high, and other inſtances of a like kind, ſhow that great advantages are- to: be gained by uſing the high wheels, and that the dif- advantage: ariſing- ſrom- the greater weight of the wheels may be diſregard- ed. The great inconvenience which attends the high wheels is the greater preſſure: upon the--cattle. on-going down hill, becauſe the ſupport which
Cc the

202 Of Wheels in general.
the cattle can give in this caſe, is very
tow placed. But, even ïn this caſe, the inſtances above mentioned, ſhow that the height of wheels may be increäſed
beyond the ordinary practice.
IT. Of the Diſh or Cavity of Wheels.
Suppoſe that a' perſon totally unac- quainted with the practice, were eim- ployed to make a cart.‘ He would na- turally make the axle ftraight, and the arms of it without taper. He would ſet the ſpokes‘of the wheels at right angles to the axle, by which means tliey would alſo be perpendicular to a level road, and thereby give the moſt perfe(t ſup- port to the carriage and its load. Such
wheels would be flat, and their ſole or
head would be parallel to the axle, But
yl Doe C nn an ank| 01
4 TV 0
diſg 1
hg It LEI ia(1 bd ar ard (129i 4 1 hoc
pF)

Uf the Diſh 07 Cavity of W heels. 203 But experience has ſhown, that ſuch
wheels are liable te great inconvenien-
cies, When going in wet and dirty
roads, all the mud taken up by the wheel comes down again upon the nave, and gets between it and the axle, and ſoon wears it prodigiouſly, Such
2 form of wheels alſo requires a great
diſtance between them, and conſequent-
ly a great breadth of road, in order to give room for the cart body and Joad- ing. Ict is alſo found, hat ſuch wheels bear hard upon the inner end of the axle arm below; and alſo, that the ſpokes are forced back in the mortices, and the wheels in time get a diſh or hollow on the ſide next the cart.
The reaſon of theſe two laſt inconve- niencies is this: It is very ſeldom that
the

504 Of the Difh'er Cavity ouf H heels, the two wheels are exactly on the ſame level. When one of them is lower than the otlicr, either by“ getting info a‘rut, or being on the lower ſide of the road, the greateſt part ofthe load ís upon thac wheel. In this ſituation, the head of the Wheel is not perpendicularly below the point of the nave, which is ſupport- ed by the ſpoke, The ſpoke itſelf leans over, and if not of ſufficient ſtrength, would break inwards. It therefore bears hard upon the inner ſide of the mor- tice, and cauſes the nave to bear hard upon the inner end of the axle arm. Experience has ſhown, that theſe in- conveniencies may be greatly removed, by ſetting the ſpokes into the nave, ſo as to point outward a little. By this
means the wheel gets what is called a diſh,

Of the Diſh or Cavity of Wheels, 59 F diſh, and the ſpokes no longer form a flat ſurface. Let us now ſuppoſe, that two ſuch wheels are put upon an axle, whoſe arms have no taper. The wheels would be as wide above as below, and the ſpokes would never be perpendicu- lar to the ground. Suppoſe now, that the two axlé arms are bent downwards, This would make the wheels cloſer be- low, and wider above, and the bend of the axle may be ſuch, as that the ſpoke which refis upon the ground will be per- pendicular. This form-of the wheels will remove ſome of the above mention- ed inconveniencies.
The wheels being wide above, the mud which is carried up by them will not fall ſo much upon the nave, and there will be greater room for the body
vf

206 Of the Diſh or Cavity of Wheeis.
of the garriage and its loading. But one
ofthe great inconveniencies ſtill remains.
When one of the wheels is in a rut, the ſpoke which is then ſupporting the carriage is leaning outwards, and bears hard upon the inner end of its mortice, and cauſes the nave to bear hard upon che inner end of the axle arm. It 1s, therefore, found more expedient not to bend the axle ſo much as to bring the two ſpokes, whoſe ends are on the road, to be perpendicular to-the horizon, or parallel to each other. They are made to be a little wider below than at the centre; by which means, when one wheel is in a rut, the ſpoke which is then ſupporting the carriage, may Þbe perpendicular, Itis even found neceß>:
ſary, that when the wheel is in this ſitu-
t1oN,
Df tiont| quii pt MY 1 i rorl3 J( 1s(8 1 tt bO: TA
chR( Fl
UY 15!
ſroreD fac diele|
1E Mat
lS
giu)>11
thizi: im
Is DE (ney 3(
buſs

|;
Ut One
mains,
|
le the
1 bears ortice, | upon [tjs not to
18 the
€ road, 010, Or è made| at the| 1 ONE ich 18| y be| eceb
ſitu-
(10N,
Of the Diſh or Cavity of Wheels. 207 tion, the ſpoke ſhould be a little with- out the perpendicular below: for the chief jolts which the wheel receives are from the outſide, and when che ſpoke is ſet a little againſt the jolts, ît is better able to reſiſt them. Experience ſhows, that, notwithſtanding all the diſh which has been given to wheels, they ſtilt go from the face, or looſe their cavity when they fail, It might, therefore, be ſup- poſed, that it would be an advantage to give the wheels a ſtill greater diſh. But this is limited by other conſiderations. The fpokes muſt be very hard driven into the nave, in order to have ſuffici- ent ſtrength. They muſt not be very much tapered at the foot, otherways they would be apt to work looſe. This being the caſe, the ſpokes cannot be ſet
Very

al DE
e R ZR
H————-
r=
208 Of the Diſh or Cavity of Wheels.(V| very obliquely into the nave, becauſe artid the wood of the nave wauld then ſtart Je TN up at the heel of the ſpoke, when It 18 2|| properly driven. o(fa lh A diſh or cavity of 32 inches may be théP: W given with ſafety to wheels of 4 feet inl Ml 8 inches diameter, and in general È inch rely 5 of diſh may be allowed for every foot of(Sì|4 diameter: tele n
The ſpokes ſhould be ſet ſo far from E 01
the outer end, of the nave, that a per- wl y pendicular from the ſole to the under| We ſide of the axle, may fall between an| mul: inch and two inches without the middle oW 1s point between the buſhes. By this es Mj preſſure on the outer buſh will be ſome-| wiel N what greater than on the inner, whent| ule the wheels are on a level. This Mould| u be ſo. For the inner part of the axle| kB|
LE|| ain|

A à per- under en an niddle Aj1s the
i,
j lome-
ewhenf|
pt}| j axle
arm
9
S
Of the Diſo or Cavity of Wheels, 9209 arm being much bigger than the outer, it has more friction, and therefore ſhould have leſs preffure. Alſo, every ſinking of the wheel below the level of the o- ther, cauſes it to preſs harder on the inner buſh. This poſition of the ſpokes remedies both theſe inconveniencies.
There are ſill ſome perſons of expe- rience, who have propoſed that‘the wheel ſhould be made without any diſh, and they propoſe to remedy the incon- venience' which ariſes from an unegual preſſure upon the outer and inner ends of the axle arm, by placing the ſpokes, not in the middle of the nave, but to- wards the outer extremity. This will only remove the inconveniency to a certain degree, and it fill leaves the o0- ther defeAs which have been already
D d mentioned

LS PS ERA E ELSE StS e
¿20 Of the Diſty ur Cavity-of Wheels,
mentioned without any remedy. The
experiment has been tried, and it has been found, that the axle arm is ftill much worn atf the inner end, and: that the wheels are much weaker, and ſoon- er faib, getting. adiſh inwards. In fhorc, the diſhing of wheels, which was not a natural thought, has- euher been found
by accident, or has been invented by
ſome perſon of great ingenuity, and
the courſe of uniform experience has
fully confirmed its advantages,
HI. Of the Length of the Naves.
Too ſhort an axle arm has too little power to guide the wheel in a ſteady di- reâtion, unleſs very tightly fitted into
the buſhes, and too long a nave is in-
convenient,
al þ ite| ond è elud N 1 M alt UE
tei!
|(1
M|
es|

little|
Of the Length of the Naves. 218 convenient, both on account of its bulk, and of the dirt which it is apt to carry. 12 inches or thereabouts feems a very
convenient length for a nave, exclufive
of the depth of che pan in the ends.
IV. Of the Taper of the Buſhes.
Ït 1s found neceſſary to line the in- fide of the nave hole with iron. This ús done by driving two iron rings, call- ed bufhes, into the oppoſite ends of the hole. The axle arm is made to fit ex- ay the inſide of the buſhes. The widenefſs ofa buſh therefore always de- termines the fize of the axle upon which it turns, and the ſmaller the buſh is, the leſs will be the friQion. The wide-
nefs muſt be ſuch as ſuits the axle requi- red

———————————————_———-
dR re: eii le C EEE
ór2 Of ithe sTapérof the: Búſpess
réd for the carriage. The ftrain upon the axle arm is chiefly at the infide buſh, and wooden axles generally reguire an inner buſh of 53 or 57 inches for ordi- nary carriages.
When ſpeaking of the diſh of wheels in the ſecond ſection, we ſuppoſed the axle arm to be without any taper, In order, therefore, that the ſupporting ſpokes may ſtand perpendicular to the ground, or nearly ſos it is neceſlary to bend the axle arms downwards, But this would be attended with a very great inconvenience. When the carriage is going upon a level road, the wheel would be continually ſliding in upon the axle, and would preſs hard upon the ſhoulder. As this is the place where
dirt is moſt apt to get in, the friGion
would
\C wound thei heateS vou!|
atu 2
bealllz€
fil d the EN| the S1 l ott dl ba v thidod! 1 exQQu 1 prqui| un 1 rela| id
Md S M

1pon vulh, lan
re
1eels UH the In Qing “the Ey(0 ¿ But “rreat NoE 18 heel [PON [pon Cre ton ould
Of the Taper of the Buſhes. 213 would be prodigioufly increaſed, and the buſhes and axle would be very much heated and worn, This inconvenience would be ſtill more ſenſibly felt upon that wheel which gets into a rut, and bears the greateſt part ofthe load,
This inconvenience is remedied by the very ſimple contrivance of tapering the axle arm. The intention, therefore, of this contrivance being to hinder the
diſhed wheels from prefling in upon
the ſhoulder of the axle, the manner of
executing it muſt be taken from theſe principles,- In the frft place then, the under ſurface of the axle arm, which reſts on the buſhes, muſt be level. If it be higher at the inner end, they will flide in and preſs on the ſhoulders. If it be higher at the outer end, they will
ſlide

214 Of the Taper of the Buſhés.
flide out, and preſs on the linch pins. In the fecond place, the ſpoke which touches the ground, or which 1s ſup- porting the carriage, muſt either be perpendicular, or muſt lean a little in- ward above, and outward below. Thefe two conditions will determine the quan- tity of taper which muſt be given to the axle and buſhes.
In the frſt place, let us ſuppoſe, that the ſupporting ſpoke muſt ſtand per- pendicular. In fig. 1. let LKBA re- preſent the taper hole through the nave. The lower fide A B muſt be level. Let E be the point of the ſole which touches the ground, Draw E D perpendicular to AB. Let QO be the centre line of the hole. This will be the line round
which the wheel really turns. ED
will
(6
vil À
upp|
(po:
(mets
10 al
Le DI y y tre A dU
ADSL|
(
- nvlge 3
MOB! 1
Mibi C

‘5
Of the Taper of the Buſhes DES will cut this line in C. Let G be the uppermoſt point of the wheel, exaly oppoſite. to E. Draw GC.- For the ſame reaſon, tliat E D'is perpendicular to A B, GF will be perpendicular to E K, the upper ſide of the. nave hole. Draw GE, cutting the line of the cen- tre in H. Then CH is the true diff of the wheel. Let the linés LK and A B meet in I. Then, becauſe the twoe triangles ECH and ICD have a com- mon angle at C, and equal angles at H and D, the angles at E and I are e- qual. Therefore the half taper of the axle and buſhes is juſt the fame cr foot as the real diſh of the wheels, and we may uſe the following proportion. As the half diameter of the wheel is to its
real diſh, ſo is the length of the nave to half

¿tó Of the Taper of the Buſhes.
half che taper of the buſhes, or to half the difference of rhe width öf the inner aná outer buſhes.
On the otlier hand, thé réal diſh of the wheels may be gathéred from the For if we draw BR parallel to the centre line O Q, then QR will be equal to OB, the half width of the outer buſh, and R A will be half the difference of the
width of the inner and oúûtér buſhes,
taper of the axle and buſhes.
or will be half‘the taper of: the buſhes correſponding to the length of the nave, which muſt. be counted on the centre line QO. Now BR is egual to O Q. Alſo, B Ris to RA as E His to HC. That 1s, the length of the nave is to the halí taper of the buſhes, as the half dia- meter of the wheel is to the real diſh.
Then

0 half
INher
(h of n the
For if
re line|
Y
4 N iK y
Of the Taper of the Buſhes. 2197 Thus, from the diſh of a wheel al- ready made, we can chuſe a pair of
buſhes which ſhall anſwer it, and taper
the axle accordingly: and from the
buſhes already caſt, we can give the
wheel the proper diſh. A pair of buſhes,
of which the inner is 55 inches diame- ter, and the outer 325, are found to an- ſwer very well, and require a real diſh of 22 inches for a wheel of four feet eight inches diametér-
In the zext place, let it be ſuppoſed, that the ſtanding ſpokes ſhould ſpread out a little below, which is thought moſt proper. This may be done cither by increaſing the diſh of the wheel, or di- miniſhing the taper of the buſhes. Thus, 1f the taper of the buſhes be what we
have now recommended, that is two
E€ inches,

218 Of the Taper of the Buſhes inches, and alſo the diſh of the wheels be 3! inches, the ſpokes will ſpread 14 inch on each ſide below.
The ſpokes may ſpread fill more, by ſetting them more obliguely.
Tt is moſt convenient to have- both buſhes made to one taper. This! will make the axle arm of one taper both at the inner and outer end. This however is not abſolutely neceſſary, provided that
the taper of each part of the axle arm
is made to ſuit the buſh which is to turn
on it.
V. Of fitting in the Buſhes.
This muft be very exaly done, other- wiſe the wheels can never run well. The

heels
read
lever i that ſ ANR
» furn
Of fitting in the Buſhes. 219
The firſt circumſtance to be attended to, is the ſetting them fair, that is, ſo that the centre line of the two buſhes may make one ſtraight line, which ſhould be the centre line of the whole eye of the wheel, or nave hole.
In fig. 2. let A B be the centre line of the eye of a wheel. Tt is plain, that ¡if the inner buſhc d e fbe ſet more down at C than at e, it will be nearer the centre line at d'than at f, and will grate upon the axle arm at d, which will both obſlruit the motion, and exhauſt the greaſe; and if the outer buſh be more ſet down atk than at h, it will be nearer the centre line at 1 than at g, which will have the ſame effedt. Their centre lines will not, in this caſe,
fall in with A B, but will ſtand at À 2
and

2/20 Of füting in the Buſhes.
and Bb. Great care muſt therefore
beitaken to avoid this, and make them ſtand fair. If batli the buſhes have one taper, their inſide ſhould run ſtraight with the lines c h and e k.
The- /zcond thing to be taken care of 1s, that the centre line of the buſhes may be perpendicular to the face of the wheel, without which the wheel cannot turn truc on the‘axle arm. This may be diſcovered by turning the wheel round an axle arm which fits it, and holding a ſteady mark to ſome place to the face of the- ring or felloes, This will touch the face all round as it turns, if the centre line is perpendicular to the face. If it does not, there is an er- ror, which, if not helped, will cauſe a
falſe motion of the wheel, and make
crooked

clore
hem one
1ght
Carê
ulhes|
“the not nay eel and € to This
‘5,
Of fitting in: thie Bufbes. 22L crooked ruts in the road, equal to the diſtance af the diferent parts of the face from the ſteady mark above men=
tioned.
VI. Of the Sole of a Wheel.
This ſhould be ſo made as to preſs fair on the road, eſpecially if the ſole or tread of the wheel is broad. When the axle is ſtraight or level] on its under ſide, the ſole ſhould make the ſame angle with the face which the taper of the buſhes makes with their centre line, ex- cept what is to be allowed for the de-
clivity of the road. Therefore uſe this
proportion. As the length of the nave
is to half the taper of the buſhes, ſo is the breadth of the ſole to the quantity
which

S7
fp EEE EEA
E e LE
C———— A—————— ps R R E EEE A
222 Of the Sole of a Wheeî.
which it ſhould be above the ſquare,
Thus, if the length of the nave be I2 inches, the taper of the buſhes two inches, and the breadth of the ſole three liches Er== cand the nner edge of the ſole ſhould be 7 of an inch above the ſquare with the face of the
wheel,
VIL. Of fitting in the Axles.
Tn garder to do this properly, we muſt know, If, what is called by the work- man the diſh of the wheels, which is very differentfrom whatI have called the real diſh, and the methods for finding it. 2dly, The way of finding the length of axle beds, which will anſwer to any given wideneſs on the road, the
axle being ſtraight below, in order
E tO

mult <“ork- 1h 1s I the ng (gt 1{0
the
der
{0
Of fiting in thè Axles; 223 to find what length will anſwer for any given hollow, and what hollow will an- wer to any given length of an axle bed. When every thing needful has been calculated, the wood for the axle muſt be prepared, and ſet out(as the workmen call ic) with great exa@nefß, that 1s, the lines muſt be truly drawn, which dire us for working the axle, ſo as to make the arms fit the buſhes, and the wheels run right on the road, and the work muſt be truly executed according to theſe lines. When near- Iy done, it will be proper for the work- man to try whether the wheels gather inwards equally on both ſides, both below and before. This he may do, by applying a line or ruler diagonal wiſe, acroſs from the under part of the
rieht
G° (=)

E
S554 Of fitting in the Axlet:
right wheel to the upper part of the leſt whéel, and then from the under part of the left wheel to the upper part of the: right wheel. If the wheels are pro- perly ſet, theſe two trials ſhould give the ſame diſtance on the line or ruler.
Thus, ſuppoſing a c, fio. 3. and bd two wheels gathering, below, between cand d. Ifb c is found ſhorter than 2 d, then cither b is to& far in, or a is too far out. Then the diſtance a b and c d ſhould be meaſured, to know if the gather is as much as is required.
N. B. This gather will always be
equal to twice the real diſh of the
wheels, If it 1s too little, a muſt be-
brought alittle in. If it is too much,
throw out b. Ifjuſt right, a mutt be
brought in, and b thrown out equally.
Of
j
¿ o

€ ef
part| of|
°DrO- 10d “uler, Elb d (een Wi)
han | 41S )» and rf the
5s be
the|
ſt ba!
uch,
tbe
Iy, 0f
VIII, Of finding the Diſh of the Wheel.
What the workmen find moſt conve- nilent to confider as the diſh of a wheel is conſiderably different from what I have called the real diſh.
Figure 4. repreſents a wheel ſeen edge-ways, and ſtanding on the level ground, with its ſole oa. The line h i, which 1s the lower ſide of the axle arm, 1s UE to belevel, or parallel to o a. The line m hf is parallel to the face of the wheel b a, andik is parallel to
the centre line À B. He is perpendi-
cular to the ground. Now, e o, the
diſtance of this perpendicular from the inner ſide of the ſole o, is called the diſh of the wheel by the workmen. Ic
FS 18

226 Of the Diſh of the Wheel.
is plain, that the diſtance of the point€,
from the like point correſponding to the other wheel, is the diſtance between the ſhoulders of the axle, or he length of the axle bed.
This being attended to, the two fol lowing methods may be taken for find=
tng tlie diſh of a wheel.
rt. By a ſquare and rule.
Let abcd(fig. 3. No. 2.) repreſn«s the ring of a wheel, gh i a ſquare, The ftock hi is applied through the eye of the wheel to the buſhes. The blade is applied to the inner end of the nave, and reaches as far up as the ring of the wheel, i Then a rule, d e f, being held
-
ſquare over it, will ſhow the diſtance
between

lent alf eye ade VE, the ld ce
N
Of the Diſh of the Wheel. 227 between the infide of the ſquare and the ſole of the wheel, which is the diſh iought, allowance being made for the diſtance of the ſquare from the buſh, occafioned by the depth of the inner
pan, if there be any.
2. By calculation.
Let a ſtraight ruler c d(fig. 4.) be
: applied to the face of a wheel, as near|
the nave as poſſible. Let a ftraight rod, lI mn, be put thro? between the ſpokes, ſquare on c d. This will ſhow the di tance mn between the face of the wheel and the inner end of the nave. Then ſay, as this diſtance is to half the taper of the buſhes, ſo is the height of the lower ſide of the axle arm(ſuppoſed
level)

228 Of the Diſh of the Wheel.
level) to a fourth guantity. This muſt
be added to the breadth of the ſole, and the ſun muſt be taken from m n. The remainder is the diſh reguired; for it is plain, that fa is very nearly equal to ik, which is egual to m n; and that ik:kh::he:ef; and alſo, that e 0 1s the difference between fa and the ſum of Fe and oA.
Thus, if the diſtance of the lower fide of the axle from the ground be two
feet, or 24 inches, and the taper of the
buſhes two inches, and the diſtance of
the inner end of the nave, from the face of the wheel, be 12 inches, and the breadth of the tread be 23 inches, we Na TT 24 2, which is f&
Then fe and o a make 43 inches This
taken from 12 inches, leaves 77 for the
diſh
)

Of the Diſh of the Wheel. 229 diſh of the wheel, or one foot three in=- ches for.two wheels.
This calculation may be done by the ſliding rule, which is much uſed by cart wrights. Set I2 to 24, and then 1 will ſtand oppoſite to‘2 for fe, and
proceed as before,
IX. To find the Length of the Axle Bed.
This is the diſtance between the in- ner ends of the two Naves:
Ts Wen the axle arms are ſtraight below, from the propoſed wideneß be- tween the wheels within on the road, take the diſh of both wheels, the remain-
der is the length of the axle bed.
_Exanmplez

230 Of the Axle Bed. J
Example, A
Wideneſs on the road within, c f,
(fig. 5.)-- 4 6 Diſh of both wheels, cd+e f E
Length of axle bed ye 2 As
The truth of this rule is plain, by inſpeGing fig. 5. where A B is the axle, c f the wideneß within on the road, c d and e f the diſh of the wheel, and a b the length of the axle bed.
2. When the axle is hollow below.
This is often the caſe, becauſe the
bed of an axle is ſometimes confined
{o

was
ed
Of the Axle Bed. 22 to a certain length, eſpecially ſuch as have iron arms, whether they are fixed fo waggons or carts. In ſuch caſes, they muſt be made hollow below, or the arm muſt be laid into the bed, with a bend downwards, in order to bring the wheels to a right gather, or make them run at a right diſtance on the road. This is alſo ſometimes neceflary, in or- der to make the tread of the wheel preſs fair on the road. Theſe circumſtances give riſe to two queſtions or problems,
1. Having given a certain length oſ axle bed, and a certain wideneſs on the road, to find the degree of hollow, that is to ſay, how far the under ſide of the axle arm ſhould be below the ſtraight,
at the out end of the nave.
Us Rule,

i| i$22 Of the Áxle Bed:
Y| E. Rule:
Y : N 4 M Find the length of the bed, whicn | Y will give tlie wheels the required wide M| neſs of the road, when thé arms re M ſtraight below. Take half the diffe- I| rence between the given length of bed, |\ and the length then found. Then ſay, M as the bicighs of the Hhder fide of the | M ſfraight axle from the ground is to thïs M half difference, ſo is the length of the UN arm to the hollow required,
vi 4 Example. ¿A
Suppoſe the given length of bed is three cet ſix inches, and the givenwide- nefs on the road four feet fix inches,
| 0| and

OF e IRtes Bed 223 ánd the wheels to have the dimenſions ot thé laſt example; namely, one foot three inches of diſh,«cc. and the height of the under ſide of thie axle from the ground two feet, or 24 inches, and the length of the arm 12 inches, then the length of the bed: will be three feet three inches by the laſt rule. The dif ference is three inches, half of which is TS inches. Theg:24 Sto rt asI12to-2 of an inch, which is the hollow requir- el:
The reaſon of this operation is very cafily underſtood.
Let A B(fg. 6.) be the given length of bed, FK the given wideneſs on the road, and let C D be the length of bed which would give the wheels that wide- neſs on the road, when the axle is
Gg ſtraight

224 Of the Axle Bed.
ftraight below. Let C E be the length of the arm. Draw C L perpendicular (to the horizon: Then: LF is the diſh of the wheels. Now, ſuppoſe the axle
bent down to the pofition C M. The
line C F will take the poſition C G, in:
fuch a manner, that the angle ECF
will be equal to the angle MCG, and:
cherefore the angle E C M will be equat
to the: anyle FC Ge Draw EM pet pendicular,to E C, and F, G perpendi- cular to C F, and GH perpendicular wo ER. E is eaſy to- ſee that CE: E
M::CF:FG,- and: that GE B-M CL: FH. Now, FH‘is half the
quantity: by. which the diſtance between:
the wheels is diminiſhed, by bending down the axle from CE to. CM& If;
therefore, A:G be made equal:to FH;
and

(VCCI ling vans FH,
and
EPA A I A 7 z Wf LBE ANL C DELS DSS
and A O be made parallel to CM, the wheel placed on the bent arm, PBA O,
will have the ſame wideneſs on the road
as when on the flraight axle Q E. Therefore A C is really the half diffe- rence between the two axle beds, when E M is the hollow or bend of the axle. Therefore the rule given is juſt.
N. B. Ict is not ſtriWy‘juſt, becauſe CT G is not equal to CF, but the dife- rence of AC or EM from the truth does not amount to the sooth part of an inch.
Queſt. Given a certain hollow E M, ánd a certain wideneſs F K on the road,
to find A B the length of the axle bed.

OF Mer Aale Bed.
D) [SS) ON
Rule,
Fd, as Delore, the lene Of DEd CD lor an axle rent below. Ihen Jay, as fe Tencth or arm CE 15 LO fe given hollow E M, ſo is the height of the lower ſide of the fraight axle from e eround CT. tod fourth number, which will be AC. Twice this, added to the ſtraight axle bed, will give the
hollow axle Ded.
Example.
Suppoſe È of hollow, and four feet ſix inches on the road are given for the wheels, which we have ſo often men-
tioned,' then I2::
À o
4E A Gi Now,

Of the Axlè Bed. 3 Now, the double of this is three inches,
| | | | | and CiD:1s: thice: feet three néthess
} therefore A B is three feet lix inches. Oed| The reaſon of this is evident from I what has been ſaid already. Li| Tn the foregoing calculation, the height Lt of| of the under fide of a ſtraight axle from u| the ground was always one of the num- A| bers to be worked with. In order to E| find this, confider figure 4. Thus it is E hi plain that h f is equal to ia, which is half the breadth of the face of the wheel, | deduéting half che width of the buſh at | 1, even with the face of the wheel. | Meaſure i h along the buſh. ik was fect| found in the way formerly directed. the I Eben we lave 1 IK ufs he; the eN height from the ground. I may here Gd ablerye, that h e will hardly ever differ Y z of |

e——————————— —————:-
Pi RE—
EES
artes TT——= M UTE RTS E E ÄSTE
238 Of the Axle Bed.
2 of an inch from hf or ia, ſo that it is
hardly neceſſary to make a calculation for it.
I conclude this part of the ſubje(&t by obſerving, that if the taper of one axle be leſs than that of another, the axle whoſe taper is ſmalleſt will require to
be farther bent down, in order to give
the ſame pair of wheels the ſame gather
below, or to put the wheels in the ſame
poſition; and the additional bend that
muſt be given for this purpoſe is juſt
equal to one half of the difference of the ¿wo tapers.
Fetithe. Axle ABDECA(gs 7:) bé firaight below, and have two inches of tapers Leti lbeithe centre: hne,;and KIT a horizontal line. Let A P be the face of the wheel, and L Q a perpendi-
cular
th80 EM frs O 4 ul
wd

Of thè Axle- Bed. 239 cular from the centre of the outer buſh. ft is plain that K L is egual to half the taper, or difference between the width of the buſhes. FI is alſo plain, that I L is to LK as LQto QP, which is half the gather of that wheel. Again, let EFEG(fg. 8.) be âñother axle,
ftraiglit below, with only one inch of
taper. MO wut, in like manner, be
half the taper, and half.of KL. SE will therefore be half of PQ. Tf, now, we make 8 T equalto PQ, we muſt bend the arm to the poſition H ŸV with its lower ſide, ſo that G V may be equat to MO. This will bring down the centre O as much further as it is already below the level M N, and then the po- ſition ot the face O T will be’ the ſame with that of the face LP, and, confſe-
quently,

240« Wfthe Axle Bed.
quently, both wheels will have the ſame
gathér belows
X. Of the gathering of the Wheels forward.
It is found; by experience, that wheels run better when they are ga- thered a little forward, or incline a little inward towards the foreſide of the axle.
The taper of the axle arm is the cauſe of this. The wheel being preſſed forward by the arm, it muſt be forced outward by the taper, unleſs it be ba- lanced by an inclination inward. The more, therefore, that the arm is taper- ed, and the leſs that the wheels are ga- thered below, the more gather forward
will be reguired.- About an inch and
a
ine
1D)

| Of rhe gathering of Wheels, 241
Mm an half of gather forward is found, by | | experience, to anſwer for wheels of | four feet cight inches luigh, with buſhes Q':| of two inches taper, and an axle ftraighe | below. | The rule for bringing wheels to their nat|) gather is this: 1A| The axte being made ſtraight on the [ile under ſide, a line muſt be drawn along Slee,| the middle of the under ſide. Then the Île| length of the arm, and of the bed, be- Ted| ing all marked out, ſet off= OL TAI Ged| inch, or a little leſs, towards the fore 2 lide of the axle, at the out heads, and he| take the points thus ſet 6 ior the S/1- centres from which the out ends are Bt /A-/ to be ſquared. 1rd But that every perſon may be ſatisfyed qnd as to the method of finding théſe diſtan- an H h CCS,

242 Of the gathering of W veels,
ces, the following proportions will an- iwer to every caſe.
As the half height of the wheel is to the fourtly part of the intended gather, ío make the length of the arm to the diſtance ſought.
This proportion may be thus demon-
ſtrated from fig. 9g.
Let abcd repreſent the under ſide
of an axle, ne fr a line drawn along
the middle of it, n o the diſtance ſet for-
ward at one out head, and ro the dif
tance ſet forward at the other.. Then, ſince the centre line of the axle muſt correſpond with the centre line of the buſhes, and the face of the wheel cuts theſe lines at right angles, if the centres of the out heads were continued in the
ſtraight line in n and r, the face of the
wheels
0 7A

Of the gathering of Wheels. 243
i 4 wheels would cut that line at right || angles, at the lines ht and mu. But | Æ| when the centre of the out heads are F° placed in o and o, the faces of the E wheels will cut the lines eo and fo at right angles, and therefore the angle o WM en and hik are equal; ſo alſo the | angles ſit and ui v are equal, ando fr Pe| and Ilim are equal Therefore, as N ih, the half height of the wheel, is to F-| hk, a fourth of the gather,(that îs a Laun fourth of the difference between hl and Æh, ſv) ſo is en, the length of the arm, to cal| n 0, the diſtance ſought, and ſo of the Je other end, becauſe il: 1m::fr:ro. 2{5| Ws? Ñ M XI. 0f e

L244]
POE O he Manner of placing the Carriage OIL
ibe W heels.
Let abcd(fig. 10.) repreſent the body of a carriage, and ſuppoſe it pla- ced on à pair of wheels, which require no packing, the half height of the wheel being n p. Suppoſe it again placed on a pair of wheels, whoſe half height is O Pp, 0 as to reguire a packing to raiſe it to the ſame height with the other, The height of the packing will then be equal to n o. In a level road this will make no difference of weight on the horſe's back, Butif the carriage ſhould be going down a road, making an angle with the horizon of about 1 5 degrees, it
will make a conſiderable difference, as
may

Of placing the Carriage. 245 may. be-ſcen.by-.the. figure, For-faps poſe i k.to- repreſent ſuch a declining road. Then, if a perpendicular to the horizon is raiſed to. the centre of the high wheel, it will cut the carriage at e g, whereas‘a perpendicular paſling through the centre of the low wheels will cut it at. fh. From this it 1s evi- dent, that the higher that any carriage is raiſed above the centre of the whecls, the greater weight will, in ſuch a cafe, be thrown on the back of the horſe, And, in going down, the horſe will have too much weight, and, in going up, too little.
The higher any carriage is thus raiſed, and the more any road declines, the greater’ will be the inconveniency, ari- fing from the additional weight which
LJ 12

246 Of placing the Carriage.
is thrown upon the horſe’s back, when going down hill, and his having too little weight on his back, when going up hill, Ic will be ſome remedy if the ſhafts or limbers of the carc be raiſed in going down hill, and lowered in go- ng up hill, which may be done by al-
tering ſome links of the back band.
Of fixing the Axle on the Carriage.
After an axle has been properly fitted nto the wheels, ſpecial care muſt be ta- ken, that it be not turned out of its right pofition by the manner în which it is fixed to the carriage. Axles are ſometimes fixed to the body of the car- riage, and ſometimes to the ſhafts or limbers, the body lying looſe above them. In whatever manner the axle is

|A
SE|
Of placing the Carridge. 247
SRE
ſlxed, ic muſt be kept, while working, in the poſition for which it was drawn« Therefore when the axle is fixed tó the body of the carriage, and that body 1s io placed as to be level when going up- on level ground, the axle muſt be fixed with the plane of its upper ſide parallel to the body of the carriage When the axle is fitted to the ſhafts, it muſt be conſidered how much higher the ſhaîts will be at the back band than at the axle, when the carriage 1s going upon level ground. This may be known from the height of the wheels, and the height of the horſe,(ſce fig, 10.) Let a ce repreſent one of the ſhafis, a È the height at the back band, and bc d a level line paſling through the upper
fide of the axle. It is plain, that to keep

548 Of placing the Carriage: keep the axle in the right poſition, its upper face muſt be kept in the line
bed. If it be mérely- applied to the
outer ſide of the ſhaft a c e, the wheels
will be made to have too much gather forward.
The right ſlope to be given to the axle or ſhaft,’ where they arefitted together, may be found by the follow- ing proportion. As the length of the ſhafc from the fore ſide of the axle to tlie back band, is to the difference be- tween the height at the axle, and at the back band, ſo is. the breadth of the axle on its upper fide, to the depth to which it muſt be let into the ſhaft, at the hind ſide more than at the fore fide. or acistoab, ascdistode.
From
T9

—————_——
Of placing the Carriage 249
From this ic is alſo Plain, that the gather forward may eaßily be either in- creaſed or diminiſhed, by the manner in which the axle is fixed on, and that a proportionable difference will, at the ſame time be made on the gather below, or wideneſs on the road.
Maſters and drivers ſhould be careful to keep the ſhafts always about the ſame height, by the manner of yoking the horſes, becauſe ſome alteration will be made by every change The buyer of a cart ſhould get from the maker a note of the difference between the height of the wheels, and the height of the back band, to which the cart was adjuſted, or the workman ſhould be enjoined to adjuſt the cart in this reſped in the manner which the buyer may think
li molt

¿ve 4
E RRE IPL PER E ft BEAR E Pf 250 Ö/ Pacing, IDE Carr ido
moît ſuitable to his horſes. Any altera-
tion occaſioned by the change of horſes, mult be correéted by altering the length ot the back band, ſo as to bring the ſhaíts to that height to which they were
adjuſted by the maker.
XII. Some Remarks on the Obſervations
made by Mr Jacob on the bending of the
Axle-arms downward.
He ſays, that the univerſality œŒ
this practice would make one apt to ſuſ- ped, that there muſt have been ſome better reaſon for ic than ſcems at preſent
readily to be given by aruúficers.
ic muſt be allowed, that experience
and facts are always ſuperior to theore-
tical reaſonings, and that every theory
COI

ML pO
Remarks an Mr Jacob's. Obſerva:ious. 258
contradicted by theſe is to be reje&ed,
kowever plaußfible ic may appear. But
9
in this caſe, theory and experience per fey agree, as will appear by conſider- ing a little the neceſſary conſequences ofthe conical form of the axle arms,
Letta Cc,(fg. II.) repreſétit any heavy body prefling upon del, df being parallel to the horizon. Then it is plain, that d e f will be preſſed from dto f. Therefore an axle, tapered off on the under ſide, prefles the buſh in this e and muſt cauſe the wheel to fly out.
Suppoſe again a heavy body, as A B (fig, 12.) prefling on another C D, and that the ſurface, by wlüch they join is horizontal, it is plain, that CD will be preſled ftraight downwards, withouc
any

——————————-=———————
——————— E
252 Remarks on Mr Facob’s Obſervations,
any tendency towards C or D FEE
pA
fore ah axle which is ſtraight below will not preſs the wheel cither outward or inward, in ſo far as ît is acted on by no other cauſe than the downward preſſure-
Again, ſuppoſe a b(fig- 13,) to VE an axle arm bending downwards, and cd to be the part of the buſh on which it preſſes. Ic is plain, that the wheels will be preſſed inwards by this form of the axle.:
I muſt now obſerve, that the axle arm exerts another preſſure upon the buſhes, beſides that which 1S diredly downwards. Far, by the draught of the horſes, it muſt alſo preſs upon the fore part of the buſh. This forward preſſure is but very ſmall in comparli-
ſon with the downward preſſure, when
the

———
-
2.
é N
Ut 72.

X. F: ci 3! S I [TV [I [3 19 IV |El E) y z
E R ==> mont fra EE eme ette E-* E

Remarks on Mr Facob’s Obſervations, 253 the carriage is going upon perfedly e- ven road, being no more than what is ſufficient for overcoming the fridion of the wheels. But every obſtacle over which the wheels are to be driven, muſt increaſe this preſſure upon the fore ſide of the buſh. From this it is evident, that when an axle is ſtraight below, the taper of the arms on the fore ſide will cauſe the wheels to preſs outwards, unleſs this preſſure is balanced by ſome other. This may be done, either by bending the axle downwards, which will produce a preſlure inwards, ſuffici- ent to balance this preſſure outwards, of which we have now been ſpeaking-
Or, it may be more perfeâly done, by keeping the axle ſtraight below, and bending it a little forwards, in the man-
ner

254 Remarks on Mr Facov’s Obſervations.
nerdireded in fect. X. It is this€eir- cumítance which gives occaſion to the gather of the wheels forward; and Mr Jacob is miſtaken, when he makes the bend of the arms, or gather of the wheels, to depend wholly upon, or be regulated by, the diſh or cavity of the wheels; and‘when he alledges that the diſh of a wheel neceſſarily requires a
bend in the axle arm, to give it a mo-
tion ſtraight forward. Whatever the:
diſh of a wheel is, the face of it will al- ways be perpendicularly cut by the centre line of the buſhes, if the wheel be truly made, and truly buſhed. Itis therefore the taper of the arm, and not the cavity of the wheels, which is the immediate cauſe of that outward preſ-
iure, which makes it neceſlary to bend
the
litis R—
— it g=

aten
Remarks on Mr Jacobs Obſervations. 255 the arms either downward or forward. Mr Jacob is indeed ſo far in the right in his aſfertion, as a difh of the wheel requires a2 taper of the arm, in order to gain thoſe advantages which are Ppropo- ſed by the diM.
But diſhed wheels may be uſed with cylindrical arms, and in this caſe the arms muſt neither be bent downwards
nor forwards; for, if they were, the
wheels would preſs violently inwards.
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Colour& Grey Control Chart 5G Blue Cyan Green Vellow Hed Magenta White Grey 1 Grey 2 Grey 3 Grey 4 Black
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