196

BRONZE.

dr pallets, which of course will drive the bricks out upon the other side, whence theyare to be removed by hand.

There is to be a small hole in the centre of each pallet, and also in the bed, for thepurpose of allowing any superfluous earth to be pressed through the moulding boxeswhen the pistons descend. And in order to cut off the projecting piece of clay whichwould be thus formed on the bottom of the brick, a knife-edge is in some way connectedto the bed of the machine ; and as the brick slides over it, the knife separates the pro-tuberant lump : but the particular construction of this part of the apparatus is consideredto be of little importance; and the manner of effecting the object is not clearly statedin the specification. .

The patentee proposes a variation in this construction, which he describes in thesewords : “ It will be evident that in place of having the moulds to rise, they may, bysuitable arrangements, be made to descend below the bricks. In this case, in place ofthe boards, stationary blocks to receive the pallets must be fixed on the bed of themachine, and these blocks must be shaped in such a manner as to allow of the mouldspassing over them ; and then it will be desirable to use the first part of my improve-ments, that of having the pallets within the moulds at the time of moulding the bricks;or in case of working with exceedingly stiff brick-earth, the pallets may be dispensedwith.” In 1835, 1,380,279,0(15 bricks paid duty in the United Kingdom ; the revenuefrom which was 405,580/. 6s. 3d.

BRIMSTONE. ( Soufre , Fr.; Schwefel , Germ.) Sulphur, which see.

BRITISH GUM. The trivial name given to starch, altered by a slight calcination inan oven, whereby it assumes the appearance and acquires the properties of gum, beingsoluble in cold water, and forming in that state a paste well adapted to thicken thecolors of the calico printer. See Starch.

BROMINE, one of the archseal elements, which being developed from its combinationsat the positive pole of the voltaic circuit, has been therefore deemed to be idio-electro-positive, like oxygen and chlorine. It derives its name from its nauseous smell, /?pi3pos..fietor. It occurs in various saline springs on the. continent of Europe, in those of Ashbyde la Zouche , and some others in England ; in the lake Asphallites, in sponges, in somemarine plants, in an ore of zinc, and in the cadmium of Silesia. At ordinary tempera-tures it is liquid, of a dark brown color in mass, but of a hyacinth-red in thin layers.Its smell is rank and disagreeable, somewhat like that of chlorine. It has a very caustictaste. Its specific gravity is 2'966. Applied to the skin it colors it deep yellow andcorrodes it. One drop put within the bill of a bird suffices to kill it. It combines withoxygen with feeble affinity, forming bromic acid. Its attraction for hydrogen being fa 1 'more energetic, it forms therewith a strong acid, the hydrobromic.

Bromine dissolves very sparingly in water, but it is very soluble in alcohol and ether.It combines with carbon, phosphorus, sulphur, and chlorine, as well as with most of themetals. From its scarcity it has not hitherto been applied to any purpose in the arts,but it is supposed to possess powerful discutient effects upon scrofulous and otherglandular tumors, whence the waters containing it are prescribed as an internal andexternal remedy in such forms of disease.

BRONZE. A compound metal consisting of copper and tin, to which sometimes alittle zinc and lead are added. This alloy is much harder than, copper, and w a *employed by the ancients to make swords, hatchets, &c., before the method of workm=iron was generally understood. The art of casting bronze statues may be traced to thmost remote antiquity, but it was first brought to a certain degree of refinement hiTheodoras and Rcecus of Samos , about 700 years before the Chrislian era, to whom t 'invention of modelling is ascribed by Pliny . The ancients wee well aware that ^alloying copper with tin, a more fusible metal was obtained, that the process of castingwas therefore rendered easier, and that the statue was harder and more durable ; aayet they frequently made them of copper nearly pure, because they possessed no inea *of determining the" proportions of their alloys, and because, by their mode of manag 1 ^the fire, the copper became refined in the course of melting, as has happened to m a ^founders in our own days. It was during the reign of Alexander that bronze statua ^received its greatest extension, when the celebrated artist Lysippus succeeded by "processes of moulding and melting to multiply groups of statues to such a degree iPliny called them the mob of Alexander. Soon afterwards enormous bronze colosswere made, to the height of towers, of which the isle of Rhodes possessed no less than ^hundred. The Roman consul Mutianus found 3,000 bronze statues at Athens, 3,'v us lyRhodes, as many at Olympia and at Delphi, although a great number had been p reV1carried off from the last to-wn. ..

In forming such statues, the alloy should be capable of flowing readily into al • ,

parts of the mould, however minute; it should be hard, in order to resist acci t0blows, be proof against the influence of the weather, and be of such a nature ^ ^acquire that greenish oxydized coat upon the surface wh'ith is so much ndmxrea