CENTRE OF GRAVITY 



29 



earth equally in parallel forces, it is evident that the centre of these 

 forces, which is the centre of gravity, will be at the middle point. Quite 

 different will be the case where the rod is made of particles of the same 

 kind, unequally distributed, and causing one part to be denser or thicker 

 than the other (fig. 16, No. 2). In this case the centre of gravity is 

 found to fall at F, in the direction of the heavier part D, where the 

 parallel forces are for equal lengths the more numerous. 



These conclusions may be roughly illustrated by taking a piece of 

 stick two or three feet in length, of uniform thickness, and placing it 



Fig. 17.— The Centre of Gravity 

 The centre of gravity is at or near the spot where the dotted lines cross 



across the edge of a knife, where it may be made to balance or brought 

 to a state of equilibrium when resting on a point about the middle of 

 its length. If now a small quantity of lead be run into one end, and 

 the experiment be repeated, the point at which the stick can now be made 

 to balance will have shifted, and will Ije found somewhere towai'ds its 

 loaded extremity. 



According to the researches of Professor Colin, the centre of gravity 

 in the horse is situated somewhere about the point of intersection of 

 two lines, one passing vertically through the trunk beliind the xiphoid 



