GRAVISTATIC HEAT 61 



molecules under strain. PRESSURE is IMPACT RENDERED 



PERMANENT. 



Thus, the force of a hammer-blow may be registered 

 on a spring-scale and its equivalent in static weight 

 determined. If now in place of showering blows upon 

 a wedge, we place a weight upon it just equal to the 

 blow's mark as registered on the scale, we shall have a 

 permanent force, other things being equal, capable of 

 delivering from instant to instant, throughout eter- 

 nity, the same amount of work as would an infinite suc- 

 cession of the blows. But if instead of driving a wedge 

 which moves, we beat an anvil which does not, we there- 

 by create an equivalent of heat in lieu of motion; or 

 by setting the w r eight on the anvil, we shall be able to 

 obtain our meed in heat in the same proportion as we 

 did before in wedge-motion. To show that this is not 

 a biased conclusion I quote from Ganot's Physics, 

 Art, 465 (repeated in new edition of 1910, Art. 453) : 



"If a body be so compressed that its density 

 is increased, its temperature rises according as 

 the volume diminishes. Joule has verified this 

 in the case of water and of oil which were ex- 

 posed to pressures of 15 to 25 atmospheres. In 

 the case of water at 1.2 C., increase of press- 

 ure caused lowering of temperature, a result 

 which agrees with the fact that water contracts 

 by heat at this temperature. Similarly, when 

 it-eights are laid on metallic pillars, heat is 

 evolved, and absorbed when they are removed/' 



In fact, this knowledge is not new, for I have 

 quoted from the edition of 1877; but it has never been 

 taken practical advantage of, although it ought to be, 

 for it is the germ of perpetual motion. That is, it 

 indicates how the indisputably infinite force of gravity, 



