62 



DRAUGHT 



CH. X 



The proportion of the total resistance due to 

 friction of the axle being small, it is evident that 

 the improvement of the road surface is more im- 

 portant than the improvement of the axle, and 

 this is shown in the orain arising from the use of 

 pneumatic tires, which is equivalent to having a 

 smoother road. 



The following tables gfive an abstract of some 

 experiments on the force required to draw vehicles 

 under different conditions : — 



Kind of Vehicle. 



Description of Road. 



Proportion 

 of Draught 

 to Weight. 



Draught in 



Pounds 



per Ton of 



2000 Pounds. 



Experiments of Morin (pp. 182, 184). 



