Conservation of Energy 87 



keep their shape, but they do tend to fill the same amount of space. 

 Putty and clay likewise have very little elasticity of form; when you 

 change their shape, they stay changed. 



Jelly and steel and glass have a great deal of elasticity oiform. When 

 you dent them or twist them or in any way change their shape, they go 

 right back to their first shape as soon as they can. 



When we imagined a man with an "elastic touch," we were imagining 

 a man who gave everything he touched perfect elasticity of form. It is 

 elasticity oiform that most people mean when they talk about elasticity. 



