36 SCIENTIFIC RECREATIONS. 



the table presses against the " weight " ; or when you strike a ball, it strikes 

 the hand with the same force 



We can communicate motion by elasticity. For instance, if we place 

 a number of coins upon a table touching each other and in a straight line, 



and strike the last coin of the line by pushing another sharply against it, the 

 piece at the opposite extremity will slip out of its place from the effect of 

 the shock transmitted by the coin at the other end (fig. 29). 



When two forces act upon a body at the same time, it takes a direction 

 intermediate. This is known as the resultant. The enormous forces exercised 



