364 On the Rejiftancc experienced by 



For the whole refiftance, then, of four-wheeled carriages 

 we fhall have : 



r> _ J ;»*Pcos. (a + 7) + ('P-i : /0 fin. (a + v)l 

 ~ 1 4 Inx? cos. (« t J) + (£?4/) fin. (•>*) J 

 But for two-wheeled carriages the refinance in the fame point 

 will he found by fection 10 and fee-lion ji to he: 



W = m -k P cos. (a + 7) + (P + £ P ■+ w) fin. {a + 7) 



But the moving power here is V = M (1 — ■— - ) cos. 7. 



II. Single Excavations. 



Section 35. 



For fingle excavations or hollows, the diftance of which 



from each other is greater than that between the fore and 



hind axles, the angle will be J = o; eonfequently we (hall 



have for the refinance to four-wheeled carriages, 



j. _ C \ m A P cos. (a + 7) + (i P + P) fin. {a + 7) 7 

 I + I * * P cos. a + pf'P.+ p<) fin. a J 



Seel ion 36*. 

 If fuch excavations occur on roads of the fecond and third 

 clafs, fig. 8, the refinance for two and four-wheeled carriages 

 in the. above point F on the former kind of roads will be. 



{imx? cos. (a + y) + (-J P 4- p ) fin. (a + 7) 1 



4- -* n% P cos. a + [\ P + f) fin. a > 



+ {i^fp) C()S - (* + y) tang.p -\- (i? -\- f) cos. a t.*|J 



R/ _ /P ^ P C0S ' (* f 7) + (P + 6 P + V) fi«. (» + 7) 1 



1 + (P + w) cos. (a -f 7) tang. « / 



And for the "latter kind of roads the refiftance will be : 



r >^Fcos. (a + 7) + (-1 P + f) fin. (a + y) 1 

 r _ 3 + iniP cos. a + (1 P + />') fin. ex. I 



] + UP + P) cos. (a + y) fin. (3 tang. | 

 * + (t P + />') cos. a, fin. 0, tang. » . J 



• p , _ f u * P cos. (a + y) + (P + b P + tt) fin. (a + y) 1 

 I + (P +'*0 cos. (a + y) fin. j3 tang. S J 



OH 

 In regard to e = -~y ; in all thefe cafes OH — QS tang. 



(a + h), where x denotes the angle which the pole IH makes 

 with the inclined plane AB when the wheel is in F. If 1 W 

 be drawn perpendicular and OM parallel to AB, the angle 



JMOI = K and fin. K = ^ • 



Example. 

 Seel ion 37. 

 Let every thing be the fame as in the example given fee- 



tioa 



