ns 



PLATE XVIII. 



Fig. 224. A pair of friction wheels, supporting one 

 end of the axis of a wheel. 1'. 214. 



Fig. 225. The centre of tiie wheel A B, passing 

 over the obstacle C, describes the path DE; that of 

 the larger wheel F G, the path II I, which i» less 

 »teep. P. 2 14. 



Fig. 226, The centre of the wheel AB describes 

 the curved path C D, in passing over the obstacle E, 

 while that of the larger wheel FG has an angle at 

 H. P. 214. 



Fig. 22T. The wheel AB, moving on a soft road 

 towards B, has to overcome the resistance of the ciirth 

 atC. P. 815. 



Fig. 228. A section of the wheel of a carriage, a 

 little dished, or inclined outwards. P. 217. 



Fig. 229. A B and G D being the straps or braces by 

 which a coach is suspended, if the centre of gravity be 

 at E, F, or G, it must move, when the carriage swings, 

 in the curve passing through the respective point. P. 

 818. 



Fig. 230. The mode of harnessing two horses, so as 

 to make them draw conveniently together: when ei- 

 tlier horse advance»-sO far that the bar A B assumes 

 the position C D, the foremost horse has the disad- 

 vantage of acting on a lever equivalent only to K F, 

 while the other horse acts on EC. P. 218. 



Fig. 231. A sugar mill. The axis K is turned cither 

 by animal force or by water: the liquor is collected in 

 the trongh B, and runs oft" in the channel C. Thex 

 openings D are for the purpose of adjusting the axes 

 of the rollers. The canes arc supplied by the liands 

 of the workmen. P. 221. 



Fig. 232. A glazier's vice. The vacuity in the mid- 

 dle shows the form of the section of the lead which is 

 drawn through it, P. 223. 



Fig. 233. A forge hammer, clevnted by the plugs, 

 projecting from an axis, either at A, or, more coiueni- 

 cnriy, at B, and thrown forcibly against the woode6 

 spring C. P. 224. - ■> 



Fig. 234. An engine for driving piles, on Vauloue's 

 construction. - The horses, drawing at A, B, raise the 



weight C, held by the tongs D, fixed in the follower 

 E, which are opened, when thty reach the summit, by 

 being pressed between the inclined planes F, G, so as 

 to let the weight fall. At the same tmie the lever 11 

 is raised by the rope I, and presses on the pin K L, so 

 as to depress the lever M N, and draw the pin O out 

 of the drum PQ; the follower then descends, and un- 

 coils the rope, its too rapid motion being prevented 

 by the counterpoise R, acting on the spiral barrel Q. 

 The motion is regulated by the fly S, ihe pinion of 

 which is turned by the great wheel T. P. 23G. 



Fig. 235. The rollers of the slitting mill. P. 228. 



I'ig. 23t3. A simple plough. A is the coulter, for 

 dividing the ground; B the share, fixed on the mould 

 board C, for turning it to the right hand; D is the rest, 

 and E,F,' the handles. P. 229. 



Fig. 237. Sectimi of a threshing mill. The corn is 

 drawn in by the rollers or feeders A, B: it is beaten 

 by the rc\ ol\ ing beaters C, D, and the straw is drawn 

 out by the rakeu E F, which discharge it at G; the 

 grain fulling through tho arched bottoms II I, I G, 

 which are formed like sieves. P, 233. 



lig. 238. A corn mill, with some of the improve- 

 ment* made in America, by Mr. I'Uicott and Mr. 

 Evans. The corn, being poured into ihc funnel A, is 

 conveyed, by the revolutions of a spiral B C, to C, 

 whence it is raised, by the chain of buckets C D, to be 

 cleaned by the revolving sievo E, and the fan F; it is 

 then deposited in the granary G, which supplies the 

 funnel or mill hopper 11; this being perpetually agitated 

 by the iron axis of the upper mill stone, shakes it by 

 degrees into the perforation of the stone; it escapes, 

 when ground, at I, and is conveyed, by means of the 

 carrier K I., RJid the elevator L M, to the cooler N, 

 where it is spread on a large surface :, it passes after- 

 terwards to the bolter O, and is received in tlie binn 

 P, from whence it is taken to bp packed in sacks or 

 barrels. Q represents the surface of a mill stone, 

 cut into furrows, in order to make it act more readily 

 on the corn. P. SS-i. 



