W2 On Painting* 



Soo lib., and G — 12 feet. From thefe values, and R and R< 

 already found, we therefore have by fe&ion 6 the velocities 

 g =5: 2*520, and g' = 2*392 feet in a fecond ; fo that thefe 

 two hories on the given road could draw the load P = 

 2400 lib., at the rate of 9072 feet in an hour with a four- 

 wheeled carriage, but with a two- wheeled carriage only 86ij 

 feet per hour. 



example II. 



SeElion 18. 



Let us affume, as before, m~ \ -, n~ T V, /> = 8o, ^ = 110 and 

 a - j. Let the load in this cafe be only P= 1400 lib., and the 

 inclination of the road a - 6°. Let the weight of the wheels 

 of the two-wheeled carriage be w == 130 lib., their diameter 

 48 inches, and the mean diameter ol the axles 4 inches: 

 fo that (j. - y T , In the laft place, let the height of the 

 centre of gravity 08 = 2 feet; h that OH == OS tang, a == 

 0*2102, and consequently e = 0*017,52. Hence vve (hall 

 have {- (m + n) xP cos. a == 29*007 



( P + p + p') fin. a. == t 6.6:200 



R = 195*207 . 



/**\P cos. a, = 23*20^ 

 (P + sP + w) fill, a =± 162*492 



ft' 1^5*097 



In this cafe, therefore, R > R', about 97> iano - For a 

 horfe, then, the ftrength of which is M ^ 400 lib., and the 

 velocity on the above road G = 14 feet per fecond, we (hal| 

 have g = 4*228 feet, and $•' = 4*466 feet. Confequently, 

 the load P 25 1400 lib. would be drawn by fuch a horfe on 

 a four-wheeled carriage 15,220 feet per hour, and on a two- 

 wheeled carriage only 857 feet further. 



[To be continued.] 



XXI. On Painting. By Mr. E. Da yes, Painter. 



To Mr. Tilloch. 

 j—^ DEAR sir*, 



X HE following effays on Taftc, Beauty, Grace, Inven- 

 tion, and Compofition, being immediately connected with 

 painting, I have done mvfelf the pleafure of fending them 

 for insertion in vour valuable Magazine. I ilia.ll be obliged 



