114 BODIES SUPPORTED IN MORE THAN TWO POINTS. 



rests upon a surface, it is no longer possible to distinguis] 

 between the three kinds of equilibrium. A rectangulj 

 body, like A in fig. 83, resting upon a plane surfs 

 behaves exactly like a body in stable equilibrium, an< 



a 



i 



FIG. 83. 



it will continue to do so, even if turned about one ol 

 its edges, as in fig. 83 B. But if the line of gravitatioi 

 moves beyond the edge, about which the body is turned 

 as in fig. 83 7, where sa has moved to the right of b 

 the body will turn over, that is, it will assume a nev 

 position of rest, indicated by dotted lines. This nev 

 position, however, is not, as in the case of a body sup 

 ported in two points, the reverse of the previous one 

 but generally some other. 



If a body be thus turned about one of its edges (fig 

 84), its centre of gravity s will describe the arcs st 

 w 5s,, and will thus be raised through a definite spaa 

 The greater this space and the heavier the body, tli 

 greater must be the w r ork, the greater also the force n! 

 quired for upsetting it ; or, as it is briefly expressed, th l 

 greater is the stability of the body. If, as is the case i| 

 the body represented in fig. 84, the centre of gravit 

 and the line of gravitation are nearer to one edge tha 

 to another, it will be easier to upset the body on tl 



