A. S. Kimball— Laws of Fr idle 



nr,e, Slid, ? loaded with 100 lbs. " 

 Coefficient of Friction. 



466' '47£ 



These experiments show the increase of friction with the 

 velocity at low speeds quite clcarlv: unci in connection with 

 the series published last March, 



hiyli velocit s. vould prov< tl high .probability of the law as 

 I have stated it, esj ■<■■ the inclined 



plane has been made to show a variation of the coefficient from 

 a low vain , to a I iv yalue again, while 



the velocity constant] v increases. 

 ■ 

 * of leather belting was hung over a easl iron pulley. To one 

 end a determined tension was given by a fixed weight; to the 

 other end v > dynamometer. The tension of 



the ends of the belt being known, the coefficient of friction was 

 '--ib found. Several pullevs were us! 1. and various kinds of 

 belting; and a considerable range of tensions was employed, 

 with uniform results. 



Two tables are here given, one selected to show the increase 

 of the coefficient at low & speeds, the other to show the 

 of a maximum coefficient at a delink, velocity. In the third 

 table, the Hist c < fun n uives tin < 



the second and third give the tensions of the ends of the belt ; 

 and the fourth gives the relative values of the coefficients found, 

 *e maximum in each case being represented by l'OO. I give 

 . e thev show variations more clearly than 

 the absolute values. 



