The second head of the invention is another construction of apparatus for moulding bricks, in this instance, in a rectangular frame. [Fig. 180.] is a front elevation of the machine; [fig. 181.], a section of the same taken transversely. a a is the standard frame-work and bed on which the bricks are to be moulded. Near the corners of this standard frame-work, four vertical pillars b b are erected, upon which pillars the frame of the moulding boxes c, slides up and down, and also the bar d, carrying the rods of the pistons e e e. These pistons are for the purpose of compressing the clay in the moulding box, and therefore must stand exactly over and correspond with the respective moulds in the frame c beneath.
The sliding frame c, constituting the sides and ends of the moulding boxes, is supported at each end by an upright sliding rod f, which rods pass through guides fixed to the sides of the standard frame a a, and at the lower end of each there is a roller, bearing upon the levers g, on each side of the machine, but seen only in [fig. 181.], which levers, when depressed, allow the moulding boxes to descend, and rest upon the bed or table of the machine h h.
In this position of the machine resting upon the bed or table, the brick-earth is to be placed upon, and spread over, the top of the frame c, by the hands of workmen, when the descent of the plunger or pistons e e e, will cause the earth to be forced into the moulds, and the bricks to be formed therein. To effect this, rotatory power is to be applied to the toothed wheel i, fixed on the end of the main driving crank shaft k k, which on revolving will, by means of the crank rods l l, bring down the bar a, with the pistons or plungers e e e, and compress the earth compactly into the moulds, and thereby form the bricks.
When this has been done, the bricks are to be released from the moulds by the moulding frame c rising up from the bed, as shown in [fig. 180.], the pistons still remaining depressed, and bearing upon the upper surfaces of the bricks. The moulding frame is raised by means of cams m, upon the crank shaft, which at this part of the operation are brought under the levers g, for the purpose of raising the cams and the sliding rods f, into the position shown in [fig. 181.]
The bricks having been thus formed and released from their moulds, they are to be removed from the bed of the machine by pushing forward, on the front side, fresh boards or pallets, which of course will drive the bricks out upon the other side, whence they are to be removed by hand.
There is to be a small hole in the centre of each pallet, and also in the bed, for the purpose of allowing any superfluous earth to be pressed through the moulding boxes when the pistons descend. And in order to cut off the projecting piece of clay which would be thus formed on the bottom of the brick, a knife-edge is in some way connected to the bed of the machine; and as the brick slides over it, the knife separates the protuberant lump: but the particular construction of this part of the apparatus is considered to be of little importance; and the manner of effecting the object is not clearly stated in the specification.
The patentee proposes a variation in this construction, which he describes in these words: “It will be evident that in place of having the moulds to rise, they may, by suitable arrangements, be made to descend below the bricks. In this case, in place of the boards, stationary blocks to receive the pallets must be fixed on the bed of the machine, and these blocks must be shaped in such a manner as to allow of the moulds passing over them; and then it will be desirable to use the first part of my improvements, 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 dispensed with.” In 1835, 1,380,279,065 bricks paid duty in the United Kingdom; the revenue from which was 405,580l. 6s. 3d.
BRIMSTONE. (Soufre, Fr.; Schwefel, Germ.) [Sulphur], which see.
BRITISH GUM. The trivial name given to starch, altered by a slight calcination in an oven, whereby it assumes the appearance and acquires the properties of gum, being soluble in cold water, and forming in that state a paste well adapted to thicken the colours of the calico printer. See [Starch].
BROMINE, one of the archæal elements, which being developed from its combinations at 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, Βρῶμος, fœtor. It occurs in various saline springs on the continent of Europe, in those of Ashby de la Zouche, and some others in England; in the lake Asphaltites, in sponges, in some marine plants, in an ore of zinc, and in the cadmium of Silesia. At ordinary temperatures it is liquid, of a dark brown colour 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 caustic taste. Its specific gravity is 2·966. Applied to the skin it colours it deep yellow and corrodes it. One drop put within the bill of a bird suffices to kill it. It combines with oxygen with feeble affinity, forming bromic acid. Its attraction for hydrogen being far more energetic, it forms therewith a strong acid, the hydrobromic.