388 THE POPULAR SCIENCE MONTHLY 



is always the possibility that the case may be an abnormal one and that 

 the growth of our country will be found to conform to no formula 

 which represents its past growth. In such a case, all empirical methods 

 are helpless. It should be added that the formula? used in this article 

 are anti-expansion formula? — that is, they do not include the insular 

 possessions of the United States. 



