RESULTS WITH THE DYNAMOMETER. 



107 



which many wagons will constitute nearly one half. 

 Hence he can not fail to see the great importance, for 

 the sake of economy, and humanity to his team, of pro- 

 viding roads, whether public or private, of the hardest 

 and best materials. 



SECTION II. 



RESULTS WITH THE DYNAMOMETER. 



Another mode of determining the resistance of roads 

 is by means of the Dynamometer* It resembles a 

 spring-balance, and one end is fastened to the wagon 

 and the other end connected with the horses. The 

 force applied is measured on a graduated scale, in the 

 same way that the weight of any substance is meas- 

 ured with the spring-balance. A more particular 

 description of this instrument will be given hereafter. 



Careful experiments have been made with the dyna- 

 mometer to ascertain accurately the resistance of va- 

 rious kinds of roads. The following are some of the 

 results : 



On a new gravel road, a horse will draw eight times 

 as much as the force applied ; that is, if he exerts a 

 force equal to one hundred and twenty-five pounds, he 

 will draw half a ton on such a road, including the 

 weight of the wagon, the road being perfectly level. 



On a common road of sand and gravel, sixteen times 

 as much, or one ton. 



On the best hard-earth road, twenty-five times as 

 much, or one and a half tons. 



On a common broken-stone road, twenty-five to thir- 



* From two Greek words, dunamis, power, and metreo, to measure. 



