12 TRANSACTIONS OF THE [nOV. 3. 



track ill good condition the friction per ton would only be from 

 4 to 4^ pounds per ton. The latter may be taken as a fair 

 average for our cars of a gross load of 25 tons, and track in 

 best condition. 



The grades upon two divisions of the Lake Shore and Michi- 

 gan Southern Railroad are short and do not exceed 18 feet per 

 mile, while on some of the others they run up to 40 feet per 

 mile. Most of my experiments were made upon the lighter 

 grades, and I found for freight trains that the locomotive gave 

 a much more economical development of power at 18 to 20 

 miles than at the slower rate of 10 to 12 miles per hour. The 

 consumption of fuel was from 12 to 20 per cent. less. These 

 ascertained facts were derided by the officials, who said it could 

 not be possible. The higher speeds were however continued, 

 and have been finally adopted, proving far more economical in 

 all respects. The saving in running time of a car from Chicago 

 to Buffalo was twenty-four hours, and a corresponding saving in 

 time of engine and crew over each division, further giving to 

 the road a much greater capacity with the same equipment. 

 The same officials, last July, 1 883, said that " the increased 

 economy due to the higher rate of speed proved to be very great, 

 and now of tener exceeded that rate of speed than ran below it." 



The average cost per ton per mile for freight in 18T6 was .56 

 of a cent, and for 1880, 1881 and 1882, about .43 of a cent. 

 Part of this reduction was due to the increased speed; the track 

 was improved but little. 



TRACK INSPECTION APPARATUS. 



Making experiments on the principal railroads, it was soon 

 noticed that the condition of the rails and track exerted much 

 more influence upon the traction of cars than was supposed, 

 upon what were called first-class tracks; so that formulas ob- 

 tained from experiments upon one railroad did not apply closely 

 upon another road. In these questions average results are not 

 what is desired, as in the end they are misleading. The mini- 

 mum and maximum results for particular miles are those of 

 special value. Studying the minimum results led at once to 

 the fact that the condition of the track was one of the most im- 

 portant elements of the total resistance to trains, and must be 

 considered in making comparisons. The sections of rails in use 

 were so different, their moments of inertia so unlike, that there 



