18300.] On the Art of Building in Pisè. 83.

It is uſual, with the moſt careful builders in pisè, to uſe rough cheap boards as binders at the angles, and, even occaſion- ally to ram 1n ends of planks with the earth, always taking care that the wood be perfeätly concealed by the ſurrounding‘earth 5 thus even the colour of the board will be preſerved for centuries. The piank< at the angles are laid in at the bottom of the mould, ſo as to paſs under the jundions of pisè work. The moft ſim- ple and eaſy ſort of work for building in pisè, is evidently a ftraightc wall, becauſe in it are no doôórs or windows, or croſs- walls; all of which require a judicious application of the end, or head of the mould, Fig. 2. To form an eſtimate of the ex- pence of buildins in pisè,* it is only neceſſary to tonſider, that two men can complete a piece of wall ſix feet high, and as much wide, in the ſpace of a day. Eighteen inches thick at bottom ſuffices for an edificè of three ſtories. Tt is uſual to inake the wall gradually thinner upwards, by a ſmall inclination of the ſides of the mould inwards. The. joiſts of the floors of a houſe thus built are beſt laid in the wall’ while making, with the precaution of laying a piece of boaid(concealed in the middle of the wall) io ſupport the joiſts. Six men are uſually employed together to carry on the work with full effe@& in one mould. A foundation of brick, or ſtone, muſt always appear above ground; in houſes, to the height of two feet, to receive all the ſplaſhing from the eaves of the houſe: in walls ſome- thing leſs; but there the top alſo muſt be covered with brick or tiles, or ſtone; for pisè would founder if rain were ſuffered to fall on its upper edge. i|

It is to be obſerved, in general, that any ornaments round the window- frames, door-caſes,&c. muſt be always laid in of brick or ſtone. To uſe wood for ſuch purpoſes is to infure de- frudtion to the building as ſoon as the wood decays. Indeed the ſhrinking and ſwelling of wood on every change of the at- moſphere, makes it accord but indifferently with pisè. There- fore the window-frames,&c. ſhould be bedded in mortar, which may thus intervene betwixt them and the pisè, i

, The earth which may be advantazeoufly uſed in pisè, is of a very comprehenſive deſcription. All earths fit for vegetation, or for brick-making, are equally fit for pisè. Clay muſt have an addition of ſand, and ſand of clay,(in the ſame manner as in brick-making). A mixture of ſmall gravel is reckoned an acquiſition. Uſually the earth which comes out of the founda- tion trenches, or cellars, ſerves for the pisè of the building. However, to inſure the ſucceſs of the work, ir will be proper for the unexpericnced to try a ſmall experiment, in the follow- ing manner. Take a bucket or ſmall tub, ſet- it in earth ſtrongly rammed around it; then throw into it ſame of the propoſed earth, and ram it with the end of ſome heavy ſtick fas in the propoſed manner of building) till ict is filed. Turn

«