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pie, however, appears to be a just one, the applicationof a number of bellowfes is too incommodious to be putin practice ; and by their disposition in one plane, roundthe furnace, great part of the fuel lies without their reach.I have therefore endeavoured to improve the contrivance ;to multiply the streams of air, to throw them in from al-most all parts of the surface, to supply them all from onebellows, and in such a manner that they may not obstructone another, but conspire as it were into one stream aboutthe crucible.

The pot, which serves as a furnace for this purpose,has a number of holes, bored at small distances, in spirallines, all over it, from the bottom, up to such a heightas the fuel is designed to reach to. The crucible is placed,upon a proper support, in the bottom; and the holes aremade, not in a perpendicular direction to it, but oblique,that the streams of air forced in through them may butjust touch it: by this means, the crucible stands out ofdanger of being cracked by the blast, and the impelledheat plays in a kind of spiral upon its surface. The pot,which served before for the blast-furnace, with an ironring on its top, receives this perforated pot so far, that allits holes hang in the cavity ; which cavity having no otheroutlet than the round aperture for the bellows, the air,blown in through this aperture, necessarily distributes it-self through the perforations of the inner pot. The innerpot may be of the largest size, as well as the outer one,the lower narrow part of the former falling into the upperwide one of the latter : it wants no addition to increaseits height, but on the contrary will be more commodious,in regard to the inspection and taking out of the crucible,if all the part above where the fuel reaches to is sawedaway : the most convenient cover for it is an iron plate,

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