670 On the Advantage of Employing 



necessary to draw the carriage was always less with the 

 broad wheels than with the narrow ones, in spite of the 

 fact that the latter were lighter. 



This difference of weight was compensated in such 

 a degree by the greater breadth of the wheels, that I 

 think I can assert that the carriage, passing over the 

 paved road on the new wheels, and loaded with two 

 persons besides the coachman and the footman, draws 

 easier, and tires the horses less, than when, on wheels 

 of the breadth of ordinary carriage wheels, it is going 

 empty over the same road at the same speed. It may 

 be judged from this how much I must be impressed 

 with the importance of the subject on which I have 

 endeavoured to throw light. 



For the satisfaction of those who desire to know 

 more in detail the results of my experiments, I will 

 give here a copy of the register that I kept when they 

 were made. 



On the highway to Versailles, between the Pont de 

 Sevres and Passy, on the pavement : — 



The force exertedjn drawing was in pounds. 



On the same route, on the unpaved road by the side 

 of the pavement, the amount of force varied at each 

 moment, according as the road was more or less 

 sandy. When the road was very good and but little 

 sandy, it amounted to : — 



At a fast walk. At a slow trot. At a fast trot. 



80 to 84 80 to 88 80 to 88 

 80 to 96 82 to roo 82 to 100 



