10 HISTORY OF MECHANICS. 



or not, inevitably accompany our mechanical con- 

 ceptions. 



In the same way, if Stevinus of Bruges, in 1586, 

 when he published his Beghinselen der Waaghconst 

 (Principles of Equilibrium), had been asked why a 

 loop of chain, hung over a triangular beam, could 

 not, as he asserted it could not, go on moving round 

 and round perpetually, by the action of its own 

 weight, he would probably have answered, that the 

 weight of the chain, if it produced motion at all, 

 must have a tendency to bring it into some certain 

 position ; and that when the chain had reached this 

 position, it would have no tendency to go any fur- 

 ther; and thus he would have reduced the impos- 

 sibility of such a perpetual motion, to the concep- 

 tion of gravity, as a force tending to produce equi- 

 librium ; a principle perfectly sound and correct. 



Upon this principle thus applied, Stevinus did 

 establish the fundamental property of the Inclined 

 Plane. He supposed a loop of string, loaded with 

 fourteen equal balls at equal distances, to hang over 

 a triangular support which was composed of two 

 inclined planes with a horizontal base, and whose 

 sides, being unequal in the proportion of two to 

 one, supported four and two balls respectively. 

 He showed that this loop must hang at rest, be- 

 cause any motion would only bring it into the 

 same condition in which it was at first; and that 

 the festoon of eight balls which hung down below 

 the triangle might be removed without disturbing 



