TAYLOR'S EXPERIMENTS 11 



ing the countershafts by the interposition of wooden packing 

 pieces under the bearing. 



Initial Tension. Each belt was spliced so that it was 

 under an initial strain with the belt at rest immediately after 

 tightening, of 71 Ib. per inch of width of double belts. This 

 is equivalent in the case of oak-tanned and fulled belts to 

 192 Ib. per square inch of cross-section; and oak tanned, not 

 fulled belts to 229 Ib. per square inch of section; semi-raw- 

 hide belts 253 Ib. per square inch of section; rawhide belts 

 284 Ib. per square inch of section. 



The belts were divided into two general classes known 

 respectively as shifting and cone belts. The shifting belts 

 were those running from the main line of shafting to the 

 tight and loose pulleys on the countershaft, while cone belts 

 extended from the countershaft to the machine. The shift- 

 ing belts had about i\ times as much transmitting power as the 

 cone belts, which latter were used according to the ordinary 

 rules of belting, such as are illustrated in the straight-line 

 formulae, Fig. i, page 7. The table, pages 12-13, * s a summary 

 of the results of the nine-year experiment as obtained from a 

 study of the records. The shifting belts were run, on an 

 average, twenty hours per day, while the cone belts did not 

 receive quite such steady use. While the shifting belts had a 

 net working load only four-tenths as great as that of the cone 

 belts, both shifting and cone belts were tightened repeatedly 

 to the same tension, namely, 71 Ib. per inch of width. The 

 cone belts were supposed to give an effective pull on the pulley 

 of 65 Ib. per inch of width, and the shifting belts an effective 

 pull of 26 Ib. per inch of width. 



Sizes and Speeds of Belts. The shifting belts ranged in 

 dimensions from 39 ft. 7 in. long, 3! in. wide and \ in. thick 

 to 51 ft. 5 in. long, 6| in. wide and 0.37 in. thick. The cone 

 belts ranged from 24 ft. 7 in. long, 2 in. wide, \ in. thick to 

 31 ft. 10 in. long, 4 in. wide and 0.37 in. thick. The speed 

 of the shifting belts ranged from 565 to 1570 ft. per minute 



