B',d:es affi'cUd by FriClLn, 17^ 



Kxp. 5. A body was taken whole fiat rurface was to its rdge 

 as 30 : 17 ; ihcfiat llde was laid upon the horizontal phme, a 

 moving force was applied, and the flage was fixed in order to 

 frop the moving iorce, in confcquence of which the body 

 would then go on with the velocity acquired until the fridion 

 had deilroyed all its motion; when it appeared from a mean of 

 12 trials that the body moved, after its acceleration cealed, 

 5^ inches before it flopped. The edge was then applied, and the 

 moving force defcended through the fame fpace, and it was 

 found, from a mean of the fame number of trials, that the 

 fpace defcribed was 7^ inches before the body lofl all its motion, 

 after it ceafed to be accelerated. 



Exp. 6. Another body was then taken whofe fiat furface was 

 to its edge as 60 : 19, and, by proceeding as before, on the flat 

 lurface it defcribed, at a mean of 1 2 trials, 54. inches, and on 

 the edge 6a 1. inches, before it flopped, after the acceleration 

 ceafed. 



Exp. 7. Another body was taken whofe flat furface was to 

 its edge as 26 : 3, and the fpaces defcribed on thefe two fur- 

 faces, after the acceleration ended, were, at a mean of 10 

 trials, 4I- and 7-%. inches refpedively. 



From all thefe different experiments it appears, that the 

 fmallefl furface had always the leaf! fri£lion, which agrees, 

 with the confequence deduced from the conlideration that the 

 friclion does not increafe in fo great a ratio as the weight ; we 

 may therefore conclude, that the friSlion of a body does not con- 

 tinue the fame when it bus different furf aces applied to the plane on 

 which it moves ^ but that the fmalleji furface will have the leaft' 

 fri6lion, 



7. Having thus eflablifhed, from the mof^ declfive experi- 

 ments, all that I propofed relative to fridion, I think it proper,. 



before 



