Draft of Wagons. 443 



544. Results of General Morin's Experiments in France, 

 General Morin, after a series of experiments carried on 

 under the French government, reached the following con- 

 clusions regarding the draft of carriages on roads : 



1. The traction is directly proportional to the load, and 

 inversely proportional to the diameter of the wheel. 



2. Jpon paved or hard macadam roads the traction is 

 independent of the width of the tire when this exceeds 

 three or four inches. 



3. At a walking pace the traction is the same for car- 

 riages with springs as for those without springs. 



4-. Upon a macadam or paved road the traction increases 

 with the speed above a velocity of 2.25 miles per hour. 



5. Upon soft roads of earth or sand the traction is inde- 

 pendent of the velocity. 



6. The destruction of the road is in all cases greater 

 as the diameter of the wheels is less, and it is Beater hy 

 the xe of carriages without springs than of carriages with 

 them. 



