CENTRE OP GRAVITY. 



19 



them together as one mass, and philosophers 

 have discovered that there is a certain point in 

 the middle of the whole collection of shots that 

 may he considered as the one point in which 

 all their gravitating power is centred, and that 

 point they call the centre of gravity; it is not 

 at all a bad name, and rather a short one the 

 centre of gravity. Now suppose I take a sheet 

 of pasteboard or any other thing easily dealt 

 with, and run a bradawl through it at one 

 corner A (fig. 3) and Mr. Anderson hold that 

 up in his hand before us, and I then take a 



Fig. 4. 



piece of thread and an ivory ball, and hang 



C 2 



