machine. K is a lever fixed upon the middle of this axis, and terminating in a hook at the end for the suspension of a weight L; this acts upon the board G by means of the levers K and a a and the rods b, to force or press the potatoes contained in the trough forwards against the cylinder, and complete the grating of them into a pulp. A line c is tied to the end of the lever K, and passing over a pulley d, hangs down within reach of the person who turns the handle of the machine: by drawing this line the weight at the end of the lever K is raised up, and by the rods b the board G is withdrawn to the extremity of the trough, and a fresh stock of potatoes falls out at the opening E from the hopper into the trough; then, the line being let go, the weight L presses the board against the potatoes, and forces them against the cylinder, which by its motion grates them away very rapidly, the pulp passing down the space between the edge of the lower board of the trough F, and the cylinder, which space is only a narrow crevice that nothing may pass down but the reduced pulp, which falls into a box or vessel situated between the frame at M. The board G is perforated with a number of large circular holes, to make an uneven surface, in which the potatoes remain steady, whilst exposed to the action of the cylinder upon their opposite sides. The tin plate covering the cylinder is of course pierced from the inside outwards, and the bur or rough edge left round each forms an excellent rasping surface, for the reduction of such substances as the present. The frame of the machine requires but little explanation, merely consisting of a square frame, containing the cylinder, and supporting the hopper. This frame stands on four legs, two of which rise up to a sufficient height to carry the pivot of the axis H. The legs are morticed into four VOL. XXV.-SECOND SERIES. Y y ground ground sells, which may be made to receive a box or chest, fitted in the manner of a drawer, to contain the pulp as it falls from the machine, or it may fall into any vessel placed underneath. The pulp in the vessels in which it is collected should be completely immersed in water, and well stirred, the separation of the farina, by its falling to the bottom, will speedily take place. The fibrous and refuse parts should be first removed, and the farina afterwards repeatedly washed, until it no longer communicates any tinge to the water it is then sent to the stove or drying apartment, put into boxes, and dried. Care should, however, he taken, that it does not dry too rapidly. Wherever the business is conducted upon a large scale, a machine for washing the potatoes should be erected, and it might be contrived to receive motion from the power that directs the grinding machine. The vessels containing the pulp should be so arranged, that a stream of water could be made to pass through them at pleasure. The pulp, after the first separation of the farina, still retains a quantity of farinaceous matter; but it will, perhaps, be more profitable to convert it into food for hogs, with such other additions as may be thought necessary, than to steep it again for the purpose of extracting any remaining portion of farina. It will be probably best to give it to the hogs boiled, along with a moderate proportion of boiled potatoes. This disposal of the refuse pulp would nearly defray the whole expense attendant upon the manufacture of the farina. This machine would operate with good effect for reducing apples to a pulp for making cyder, as it is extremely expeditious and effectual in its operation. * Models of two machines proper for washing the earth from potatoes may be seen in the Society's repository. Mr. Mr. WHITE, of Woodland, in the County of Durham, during a Correspondence with the Society of Arts, having informed the Secretary, that his deceased Father had been favoured with Nine Gold and Two Silver Medals from them, for planting the Trees he is now converting to a valuable Purpose; the Society thought it would render an essential Service to the Public, to trace the Progress of the Trees, from the Time of their being planted to that of the Application of their Bark for tanning; and therefore directed the Secretary to make the necessary Inqui ries for that Purpose from Mr. WHITE; in answer to which the following Communication was received. From the TRANSACTIONS of the SOCIETY for the Encou ragement of ARTS, MANUFACTURES, and COMMERCE. SIR, Woodlands, Sept. 10, 1813. I AM favoured with your's, containing a number of queries, which you request me to answer, by giving an account of the formation and progress of my plantations at this place; an undertaking I shall enter into with very great pleasure, and be equally glad if the humble production of my pen meets with the approbation of the Society, and is found useful to the public; but, I must observe, that, after the correct description given by my late father, in two letters addressed to them, one dated January 31, 1786, which is inserted in their fifth volume, and the other August 30, 1796, it will not be in my power to make a statement of his proceedings without being liable to repetition. In answer to the first part of your inquiry, I must observe, that the trees, for which he was honoured from Y y 2 the |