424 THE STRENGTH 



I next attached a weight w; to a pohit of the 

 triangle near to L, 6 J inches from the central 

 spring, by a string passing over the pully I, 

 and an equal weight w' to another point, \ an 

 inch on the other side of that spring; and 

 increasing the weight at E, so as to bring the 

 base LM perpendicular to the horizon, (which 

 was done in all the experiments,) I found that 

 the whole turned round the central spring as 

 before, though the distances of the equal weights 

 from the central spring were as 13 to 1. 



I afterwards put weights to other points, 

 passing over all the pullies, G, H, I, at once, 

 putting sometimes a large one over G, and a 

 small one over I, and sometimes the reverse; 

 and, doing in like manner by the pullies near 

 the corner C, I found that the apparatus always 

 turned round the central spring, without its 

 being bent, whiBn the sums of the weights on 

 each side were equal. But, if the sums of the 

 opposing weights were unequal, the triangle 

 no longer turned round the central spring, but 

 round some other point, at which there was an 

 equality between the negative and affirmative 

 forces. 



It is evident that we might have substituted, 

 for the weights in the above experiments, springs, 



