no THE ANATOMY OF SCIENCE 



decidedly on the side of the purely geometrical 

 interpretation. 



We shall, however, find it far safer to speak 

 of a "curved" geometry, which simply means a 

 geometry with rules of operation which are 

 more like those used in the geometry of naviga- 

 tion than they are like those used in the geome- 

 try of Euclid, rather than to speak of a curved 

 space. Let us not allow our old enemy, the ether, 

 with his stresses and strains, to reenter our 

 domain, during his term of banishment, under 

 an assumed name. 



In all our discussion of gravitation it is as- 

 sumed that we are dealing with bodies which are 

 not charged electrically. If we are dealing with 

 two objects, let us say the size of matches, a 

 single electron, extremely minute as it is, is 

 sufficient, when added to each object, to over- 

 come gravitation and change attraction into 

 repulsion. The smallness of the gravitational as 

 compared \^^th the electrical effect, has led a 

 number of physicists to wonder whether the 

 whole of gravitation may not be a small resid- 

 uum of electrical attraction and repulsion. It 

 would require only minor changes in the ac- 

 cepted laws of electricity to account for such a 

 residuum, and we know that some alteration 



