118 BOMERANG. 



forces balance, or equalize each other. At that 

 moment the weapon would fall towards the 

 ground, were it not for its flat surface and rota- 

 tory motion ; but in consequence of the centre 

 of gravity being so placed that it will always 

 present its broad surface to the air, it cannot 

 descend perpendicularly, but slides down the in- 

 clined plane, up which it has been thrown, in 

 consequence of the whirling motion continuing 

 after the projectile force has ceased ; so that if 

 properly thrown, it will pass over the head of 

 the thrower, and often to a considerable distance 

 behind him. On the same principle, a hoop 

 thrown from the hand with a spinning-motion 

 inwards, will begin to return before it touches 

 the ground ; and also the curious, though not 

 so familiar instance, of a ball fired from a 

 musket, the barrel of which has been bent to the 

 left, being carried at long distances considerably 

 to the right of the object aimed at, in consequence 

 of the rotation of the ball on its axis, caused by 

 the friction against the right side of the barrel 

 overcoming the projectile force, and thus car- 

 rying it across the line of aim. 



" The bommarang may be illustrated in a 

 room, by merely cutting a piece of card into the 

 same shape as the diagram ; then holding it be- 

 tween the finger and thumb of the left-hand, at 



