140 THE ANATOMY OF SCIENCE 



he can swim ten yards or a hundred yards with- 

 out drowning and only later becomes aware 

 that without swimming at all he can float, 

 buoyed up by the water itself. 



The validity of thermodynamics is independ- 

 ent of mechanics. In fact, the science of mechan- 

 ics is not altogether satisfactory ; a study of 

 the specific heats of substances has shown that 

 it is necessary to make some change in the as- 

 sumptions of mechanics, but we do not yet know 

 what change must be made. Yet even if we had 

 a science of mechanics so complete that it would 

 not require alteration for another century ; even 

 if we could solve the problem of two bodies or 

 three bodies or a hundred bodies; what would 

 we do when we came to a million .^^ The mere 

 description of the initial state would occupy us 

 for a lifetime. The mechanical method does not 

 reach far enough. We may measure the dimen- 

 sions of our garden with a footrule, but we do 

 not try by the same method to find the distance 

 of the stars. 



It is the field of the highly complex that 

 thermodynamics claims as its own. This science 

 is based upon two fundamental principles, of 

 which the first deals with the conservation of 

 energy. It would be interesting to trace the his- 



