17991 Manufaëtures and Uſeful Arts: 139

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ancient ſword-blade of copper, which appeared to have been fabricated before the introdu&tion of iron into general uſe,—that the coppér of that remote antiquity, was not pure copper, but a mixture of 167 parts of tin with 887 parts af Pure COPPECT.

Mr. Tuss, profeſſor of mathematics at St, Peterſburgh, has lately, by 2 very curious examination of the mutual reſiſtance between carriage-wheels and high roads, evinced—that, on roads which are firm, level, ſmooth, and dry,— and on roads which are ſtony and rugged,—carriages with only two wheels, are fitter to be, uſed, than carriages with four wheels; but that, on the other hand, the uſe of carriages with four wheels, is the moft advantageous on roads of ſand-mud which are wet, deep, and conſiderably broken.

The RuRaL SocIETY of Copenhagen, have oftered a prize for the beſt Eſay, oz the production of avo0d, for fhip-building.

They wiſh the Eſſays which ſhall, in conſequence of this, be offered to them, to explain—

What ſoil and ſituation are the moſt ſuitable for the growth of ſuch wood?

What attentions are requiſite in rearing it?

Whether it may be bended in its growth, without injury to its ſtrength?

At what age the trezs ougat to becut down for uſe?

And whether it may be of ſervice, to rip them of the bark, before they ſhall be cut down?

Mr. Danzel of Hambourgh, ſometime ſince, contrived a new ſpecies of veſſel, adapted to traverſe the ocean, without fails. It is moved by a ſort of helm or oar, of which the expanſive extremity is adapted to contra itſelf be- fore the preſſure of the water, when it is advanced; but, on 1he contráry, when it is drawn back, to ſpread out, and in ſuch a manner to gra þ—as ic were, the water, that thé veſlel is neceſſarily mecved forward, while it is drawn in.

Mr. Cavander of Sweden, has recently propoſed the uſe of a mixture of rye and potatoes, as a ſubſtitute for coffe. He direéts the potatoes and the rye to be boiled together, then baked into cakes, the‘cakes to be dried to a degree of calcination in the oven—then to bé ground into a powder, and uſed as coffee. The Royal Medical College of Stockholm, have given their atteſ- tation, that this ſubſtance affords a beverage nearly of the ſame fiavour and taſte as coffee, and perfeéily ſalutary.

To encourage foreign artiſts, manufa@urers, and artiſans, to ſettle in the Pruſſian dominions—the Pruſſian monarch has, by a recent edit,‘promiſed to ſuch, a number of immunities, advantages, and pecuniary rewards, which beſpeak at once the poverty of Pruſſia, the beneficent intentions of its Sove- reign, and the frong probability there is, that at leaſt all induſtrious Britiſh artiſans may live much better at home, than in the beſt circumſtances they can hope, abroad.

The compoſition of a varniſh for earthern veſſels, which is entirely free from that dangerous ingredient lead, has been recently made known by Profeſſor Fuchs to the’academy for uſeful ſcience at Erfurt. To form it, he takes one ounce of pyrites, one ounce of pounded glaſs, two drachms of common ſalt, half an ounce of pipe clay, one ounce and a half of borax; fuſes theſe ingre- dients together; and holds them thus in fußon tor a quarter of an hour. This varniſh is put upon the earthen pots, after they have been already, for ſome time, in the fire. After receiving it, they are expoſed again to the fire Íor the ſpace of ſeventeen or eighteen hours,

Mr. Archibald Hamilcen Rowan of treaſonable and fugitive fame, having eſcaped to America, had there formed an extenſive eſtabliſhment for the þriztizz of callicoes, It is as yet too early in the progreſs“ of American induſtry, for fuch eſtabliſhment to prove immediately profitable. Mr. Panulton Rovast, thereforé, advertiſed, a public ſale of his works to take place on the 1- July lait, offring immediate poſſeſſion of his manufaéory, to any, purcha- ſer, for one half of the ſum he had expended in forming it.