fxeneral Notices. 297 



(like the large ones b b) made of wood : they are 14 in. in diameter, and 6 in. 

 broad at the rims, with a very slight hoop of iron round them. Their axles, 

 which are of iron, are screwed to the frame, and are about 1^ in. in diameter. 

 The wheels are placed as near the front of the frame as possible, the reason 

 for which will appear when the general description of the machine is given. 

 The wheels b b are connected with the main axle d, in such a manner as that 

 they may turn upon it, similarly to a carriage-wheel, without moving the axle 

 with them ; or they can be fixed to it at pleasure, so as to turn it round 

 with them as occasion requires. For this purpose, the holes in the naves 

 are circular ; and of course so much of the axle as passes through them is 

 round. There are cross flenges, cast upon the nave, which catch hold of 

 the coupling box e when the machinery is to be moved, and are disengaged 

 from it by the handle f when the machine is going without moving the 

 machinery. In the drawing this part of the apparatus is entirely concealed 

 at one of the wheels, except a small portion of the handle at h. The other 

 coupling box is but faintly represented at e. The handle f has a joint in 

 it, which is fixed to the other half of it, which passes through the frame of 

 the machine, and terminates with the handle h; so that both coupling 

 boxes can be managed by the driver, standing at h, although they are on 

 opposite sides of the frame. The main axle d is 3A ft. long between the 

 shoulders, and 8 in. from the shoulders to the coupling box : the frame of 

 the machine is 4 ft. broad, by 7 ft. long. Fixed upon the main axle d is the 

 beveled wheel i of 60 teeth, part of which is seen in the plate. This 

 beveled wheel moves two pinions of ten teeth each. These pinions are 

 concealed in the plate by the frame of the machine : one of them turns the 

 crank-rod k, and the other gives motion to the coupling wheels l l upon 

 the top of the frame. The crank-rod k being thus put in motion as the 

 machine moves forward, the crank in, which gives motion to the cutters, 

 revolves with a uniform and steady motion, n is a coupling strap of iron, 

 which connects the crank m and the movable bar o o together, which is 

 kept in its place by means of the sliding hooks p p working in the brass 

 sockets q q, which are screwed upon the strong iron supports r r. It is 

 obvious that as the crank m revolves, it will, by pulling the connecting rod 

 n, give a perpetual motion backwards and forwards to the movable bar o o. 

 In order that there may be as little friction as possible to the movable bar 

 o o, there are two friction pulleys fixed to the iron supports r r, upon which 

 the movable bar o o rests. These are not seen in the plate, as they are 

 placed immediately below the bar ; but to any person who considers the 

 thing attentively, they must be readily understood. They are of the greatest 

 consequence, as the back parts of the cutters wholly rest upon the movable 

 bar o o ; and from the spring which each cutter must necessarily have, the 

 pressure upon it is very considerable. 



With respect to the cutters, it may here be remarked that the greater 

 body of them is made of iron, edged with the best of steel, hardened as 

 much as they will bear, without breaking out into chips when the machine 

 is in operation. The cutter-bar (that is, the bar upon which the cutters are 

 screwed) is strongly screwed upon the extremities of the supports r r, and 

 is 6 ft. long by 3 in. broad, and three fourths of an inch thick. The lower 

 or fixed cutters s s s are made triangular, of solid iron, edged with steel, 

 as before mentioned: they are 15 in. long from the point to the extremity, 

 4 in. broad at the base, and nearly one fourth of an inch thick : they are 

 steeled only to the front of the bar, thus leaving a steeled edge of about one 

 foot. In the middle of the base of the cutter there is a hole pierced, half 

 an inch in diameter, and a corresponding one in the bar where it is to be 

 placed. The hole in the bar is screwed ; and, in fixing a cutter, a bolt is 

 passed through the hole in the base, and screwed tightly down into the bar. 

 To prevent a cutter from shifting its place, there are other two small holes 

 pierced, one on each side of the half-inch hole in the base, and correspond- 



