OF
A ROTATORY CHOCOLATE MILL.
[Figures 1 & 2] of [Plate 47], exhibit this Machine. It is, merely, an attempt to effect, by power and a rotatory motion, what is done by hand and a vibrating one. To understand this latter, my readers (who have not seen chocolate made) will suppose a metallic rolling-pin, but cylindrical held in both hands, and moved parallel to itself, over a slab of marble, to and from the person employed; who holds the instrument fast when pushing it from him, and suffers it to turn a little every time he draws it towards him. He thus presents, sometime or other, every particle of the chocolate to every part of the slab and the roller: and this is also done by the Machine shewn in [Plate 47]. In [figs. 1 and 2], A represents a cylinder of stone or metal, used instead of the aforesaid slab; and B a cylinder answering to the roller in question. The latter is placed, by it’s axis, on two forks a b, so as to lean, by it’s weight, obliquely against the cylinder A, which it does less or more heavily as the forks, or stands a b, are placed nearer or farther off from the general centre. Further, the motions of these two rollers A and B, are connected by two equal (or nearly equal) wheels c d, by which, when A is turned, B turns also; but so as to give the surface of the latter much less velocity than that of A, though in the same direction. By these means, all the matter adhering to both cylinders (for chocolate is made in an unctuous state) is at one time or another, brought into intimate union, and ground together; and thus is the usual problem resolved, on rotatory principles: nor need we mention the several scrapers, &c. that would be applied to gather up the paste to the middle of the rollers, when spread abroad by the grinding process.
It may not be useless, just to say here, that this is likewise a good mill for grinding paint or oil colours.
OF
A ROTATORY MANGLE.
