In this a cylinder of from 4 to 5 feet in diameter, and only about 18 inches wide inside, is made to revolve upon an axis, which is fixed by a pin during the revolution of the cylinder. The flour is admitted by a door in the periphery, which closes air and water-tight; and the water or liquor passes through a longitudinal perforation in the axis, and thence through small holes amongst the flour, in quantities which are regulated externally by a cock. By the rotation of the cylinder the dough is made to be continually ascending on one side of it, whence it falls over upon the portion below. When the mixture becomes pretty intimate and uniform, its adhesive property causes it to stick to the sides of the cylinder, and the dough would then be carried round without much advancing the process, were it not for another simple contrivance: this is a knife-edge or scraper, 18 inches long, which is fixed along the top of the cylinder in the inside, so as barely to touch its surface; the knife is fixed to two flat arms extending from the axis, and these arms have sharp edges so as to scrape the sides of the cylinder; thus the cylinder is kept constantly clean from the sticking of the dough, which, as soon as it ascends to the top of the cylinder (if it does not tear away of itself) is shaved off by the knife, and falls down with great force upon the bottom; and as this effect is constant during the motion of the cylinder, it must be evident that the process of kneading is soon completed by it.
When that is done, the door of the cylinder is opened, and the contents discharged into a recipient beneath; at which time the scraper is caused, by a winch on the axis, to make one revolution of the now fixed cylinder, which clears off any adhering dough, and projects it through the door-way. As the dough in this machine may be said to knead itself, there being no arms, beaters, or agitators whatever, it is calculated that the power saved by it is very considerable, while, from the simplicity of its construction, the cost is moderate.
The patentee is at present engaged in combining with this kneading machine an apparatus for preparing carbonated water, highly charged with the gas, with which he proposes to mix up the flour to form dough, for the purpose of making the bread spongy or vesicular, without having recourse to the fermentative process; the result of which process, under the most favourable circumstances, he considers to be detrimental to the health of those that eat the bread, (owing to the deposition of fermentable matter in the stomach,) while it is destructive of a portion of the nutriment of the flour.