The cutting-plate is at

tend upward and form the feeding-roller frame. tached in front of the latter portion of the frame-work, and is dressed truly off for the passage of the knife over its face. The feeding-trough e is connected in

the fore-part to the roller-frame, and along its bottom to the upper edge of the side-frames. The back end of the trough is supported in a light wooden frame. The principal shaft ƒ is supported on two projecting brackets g and h, and upon it is mounted the single-thread screw i, and the fly-wheel k; on the extreme end also of the shaft the winch-handle 7 is attached. A bracket carries one end of a small shaft, on which the screw-wheel n, of 21 teeth, is mounted, and is turned by means of the screw, when the fly-wheel is put in motion. On the opposite end of the small shaft n, a spur-wheel is also placed, and acts upon another of equal diameter placed on the axle of the lower feeding-roller. This last, as well as the upper roller, are furnished with the usual long-toothed pinions, for admitting of the rise and fall of the upper roller. The upper roller is supported in a light frame that rises and falls in a slide of the roller-frame, and this is acted upon by a lever and weight, of which the hook only is seen in the figure at o. The cutting-knife p is 18 inches in length, and 4 inches in breadth. It is firmly bolted upon the arm of the fly-wheel, and its cutting edge, which is convex, is so formed that every successive point, in passing the edge of the cutting-plate, forms equal angles with the edge of that plate. In many of the

disc machines, the cutting edge of the knife is concave, formed on the same principle of equal angles; and, in effect, is the better of the two.

(1598.) The dimensions of the principal parts of this machine are as follows. Width of the frames 14 inches; length of cast-iron frames 30 inches, and height 3 feet; length of feeding-rollers 12 inches, and their diameter 44 inches; length of feeding-trough 5 feet, and width 12 inches. The fly-wheel is 4 feet 3 inches diameter, and the height to its centre is 3 feet. From the entire weight of the fly-wheel being supported at one angle of the frame, the spreading brackets qr are attached, to give the machine stability.

(1599.) The Steaming Apparatus.-The means employed for cooking food for horses and cattle, are either boiling or steaming. In the first, an open vessel is of course employed, in which the roots or other substances are placed, with a sufficient quantity of water. This method has been found inconvenient in many respects; and when the establishment is extensive, the vessel is required to be incommodiously large, and is withal not economical.

(1600.) Steaming in a separate vessel has been adopted in preference to the former method, and has been followed in a variety of forms, but these may be ranked under two distinct kinds. The first is an open vessel, a boiler, generally of cast-iron, having a channel or groove of 1 inch wide and 2 inches deep formed round its brim. The vessel is placed over a furnace properly constructed, and is partly filled with water. The groove is also filled with water. A sheet-iron cylindrical pan, of 3 to 4 feet in depth, and of a diameter suited to pass into the groove of the water-vessel (which is generally about 3 feet diameter), is also provided. The pan has a perforated bottom, to admit steam freely from the lower vessel. It is also furnished with an iron bow by which it can be suspended, and by which it can be conveniently tilted while suspended. This is the steaming pan; and for the purpose of moving it to and from the boiler, a crane, mounted with wheel and pinion and a chain, completes the apparatus. To put this in operation, the pan is filled with the substances to be steamed, and covered over either with a deal cover or with old canvass bags. It is then placed upon the boiler by means of the crane, and the fire being pretty strongly urged till the water in the boiler gives off its steam, which, passing up through the bottom of the pan, and acting upon the contents, produces in a few hours all the results of boiling. The water in the groove of the boiler serves as a sealing to prevent the escape of steam without passing through the pan. But notwithstanding this, it is evident that the steam can hardly ever reach the temperature of 212°; and hence, this apparatus is always found to be very tardy in its effects. When the contents of the pan have been found sufficiently done, the whole is removed from the boiler by means of the crane, and tilted into a large trough to be thoroughly mixed, and from thence served out to the stock. A general complaint has been urged against this construction of apparatus, arising from the slowness of the process of cooking by it, and consequent expense of fuel. Boilers of the form here described are not well calculated to absorb the maximum of caloric that may be afforded by a given quantity of fuel, neither is the apparatus generally the best adaptation for the application of steam to the substances upon which the steam has to act. Such boilers, as already observed, can never produce steam of a higher temperature than 212°. If they did, the shallow water-luting, formed by the marginal groove, would be at once thrown out by the steam-pressure; for it is well known, that the addition of 1° to the

temperature of the steam increases its elasticity equal to the resistance of a column of water about 7 inches high. A groove, therefore, of 7 inches in depth would be required to resist the pressure, which would even then be only lb. of pressure on the square inch. Under such circumstances, the temperature in the steaming-pan will always be under 212°. Hence the tedious nature of the process by using this apparatus.

(1601.) The apparatus which deserves the precedence of the above mode is here represented in fig. 290. The principle of its construction is that of a closed boiler, in which the steam is produced under a small pressure of 3 to 4lb. on the

inch. It is then delivered through a pipe to one or more separate vessels containing the substances that are to be cooked; and these vessels are so arranged as to be readily engaged or disengaged with the conducting steam pipe. The outline abed of the figure represents a section of the steaming-house, with the apparatus in due order of arrangement, and of the extent that may be capable of

supplying an establishment of from 10 to 16 horses. The boiler e is of a cylindrical form, 20 inches in diameter and 4 feet in length. It is set in brickwork f, over a furnace of 14 inches in width, with fire-grate and furnace-door. The brick building requires to be 6 feet 6 inches in length, 4 feet 6 inches in breadth, and the height about 3 feet 6 inches. The furnace is built with a circulating flue, passing first to the further end of the boiler, then turning to right or left according as the chimney may be situated, returns to the front of the boiler, and terminates in the chimney on the side opposite to the first turning. The flues should be not less in width at the upper part than one-fourth the diameter of the boiler; and their height will be about one-third the diameter. The steam-pipe is attached to the boiler at its crown, takes a swan-neck bend downwards to within 12 inches of the floor at g, and terminates at p; it is furnished with as many branch nozzles as there are intended to be steaming-vessels. The steam-pipe may be either cast-iron or lead, and 2 inches diameter in the bore. The receptacles or steaming-vessels h h are usually casks of from 50 to 100 gallons contents. They are mounted with 2 iron gudgeons or pivots, placed a little above mid-height; they are besides furnished with a false bottom, supported about 3 inches above the true bottom; the former being perforated with a plentiful number of holes, to pass the steam which is introduced between the two bottoms. The connection between the steam-pipe and the receptacle may be either by a stopcock and coupling screw-which is the most perfect connection—or it may be by the simple insertion of the one nozzle within the other, in the form of a spigot and faucet. In this latter case, the nozzle that leads from the steam-pipe is stopped with a wooden plug, when the receptacle is disengaged. Besides the steam-pipe, the boiler is furnished with a pipe i, placed in connection with a cistern of water k, the pipe entering into it by the bottom, and its orifice closed by a valve opening upward, the lower extremity of the pipe passing within the boiler to within 3 inches of its bottom. A slender rod passes also into the boiler through a small stuffing box; and to its lower end, within the boiler, is appended a float, which rests upon the surface of the water within the boiler. The upper end of this rod is jointed to a small lever which has its fulcrum supported on the edge of the cistern a little above k; the opposite end of the lever being jointed to a similar but shorter rod, rising from the valve in the bottom of the cistern. This forms the feeding apparatus of the boiler, and is so adjusted by weights, that when the water in the boiler is at a proper height, the float is buoyed up so as to shut the valve in the cistern, preventing any further supply of water to pass into the boiler, until, by evaporation, the surface of the water has fallen so far as to leave the float unsupported, to such extent as to form a counterpoise to the valve, which will then open, and admit water to descend into the boiler, until it has again elevated the float to that extent that will shut the valve in the cistern. By this arrangement, it will be perceived, that the water in the boiler will be kept nearly at a uniform height; but to accomplish all this, the cistern must be placed at a certain fixed height above the water in the boiler, and this height is regulated by the laws which govern the expansive power of steam. This law, without going into its mathematical details at present, in so far as regards this point, may be stated in round numbers as follows:-That the height of the surface of the water in the cistern must be raised above the surface of that in the boiler, 3 feet for every pound-weight of pressure that the steam will exert on a square inch of surface in the boiler. Thus, if it is estimated to work with steam of 1 lb. on

the inch, the cistern must be raised 3 feet; if 2 inches, 6 feet; 3 inches, 9 feet; and so on. If the steam is by any chance raised higher than the height of the cistern provides for, the whole of the water in the boiler may be forced up through the pipe into the cistern, or until the lower orifice of the pipe, within the boiler, is exposed to the steam which will then also be ejected through the pipe; and the boiler may be left dry. Such an accident, however, cannot occur to the extent here described, if the feeding apparatus is in proper working order; and its occurrence to any extent is sufficiently guarded against by a safety-valve.

(1602). The safety-valve of the steam-boiler is usually a conical metal valve, and always opening outward; it ought always to be of a diameter large in proportion to the size of boiler and steam-pipe, so as to insure the free egress of any rapid generation of steam. For a boiler of the size under consideration it should be 2 inches in diameter on its under surface-that being the surface acted upon this gives an area of fully 3 square inches; and if loaded directly, or without the intervention of a lever, for steam of a pressure of 1 lb. on the inch, it will require 3 lb.; if 2 lb. on the inch, 6 lb.; if 3 lb. on the inch, 9 lb., and so on. With these adjustments, the steam, should it rise above the proposed pressure, will, instead of forcing the water through the feed-pipe, raise the safety-valve, and escape into the atmosphere until the pressure is reduced to the intended equilibrium.

(1603.) Another precautionary measure in the use of the steam-boiler is the gauge-cock, of which there are usually two, but sometimes one, a two-way cock; they are the common stop-cock, with a lengthened tail passing downward, the one having its tail terminating about 1 inch below the proper water level in the boiler, the other terminating 14 inch above that level, which allows a range of 3 inches for the surface of the water to rise or fall. The first, or water-cock, then, when opened, will throw out water by the pressure of the steam upon its surface, until the surface has sunk 1 inch below its proper level, when steam will be discharged, thus indicating the water in the boiler to be too low, and that measures should be taken to increase the supply. When the second, or steamcock is opened, it will always discharge steam alone, unless the water shall have risen so high as to come above its orifice, in which case the cock will discharge water, indicating a too large supply of water to the boiler, and that it should be reduced; for this purpose, the feed-pipe i is provided with a stop-cock m, whereby the admission of water can be entirely prevented at the pleasure of the attendant.

(1604.) The foregoing description refers to a steaming apparatus of the best description, and implies that the water-cistern can be supplied either from a fountain-head, or that water can be pumped up to the cistern. But there may be cases where neither of these are easily attainable. Under such circumstances the feed-pipe may rise to the height of 4 or 4 feet, and be surmounted by a funnel, and under it a stop-cock. In this case, also, a float with a wire stem, rising through a stuffing-box on the top of the boiler, must be employed the stem may rise a few inches above the stuffing-box, in front of a graduated scalehaving the zero in its middle point. When the water is at the proper height in the boiler, the top of the stem should point at zero, and any rise or fall in the water will be indicated accordingly by the position of the stem. To supply a boiler mounted after this fashion, the first thing to be attended to, before setting the fire, is to fill up the boiler, through the funnel, to the proper level, which