ox THE RESISTANCE OF ROAD VEHICLES TO TRACTION. 





Third Series of Tests, November 1895. 



Course A. 

 ilaciidam, foirly 

 good coudition, 

 sliglitly damp. 

 Gradient, 1'5 jier 

 cent. . 



Course B. 

 Good regular pave- 

 ment, dry and 

 clean. Gradient, 

 1'2 per cent. 



Course C. 

 Bad, irregular 

 pavement, flintv 

 D"Allier. Gradi- 

 ent, 1'9 per cent. 



Course D. 

 Macadam in good 

 condition. Gradi- 

 ent, 6'8 per cent. 



Course E. 

 Macadam, badly 

 kept, wheel ruts. 

 Gradient, 5 per 

 cent. . 



The results of these tests (shown in fig. 4) only go to confirm the two 

 previous series of tests, and markedly show the worse the ground the 

 greater the economy in using pneumatics. Tests were not taken with iron 

 wheels over Courses D and E, on account of the great shocks destroying 

 the instruments. 



Fourth Series of Tests, January 1896. 



In the previous experiments errors crept into the results, but this series 

 clears them away. 



The normal speed was about 10"5 km. per hour. 



Fourth Series of Tests. 



