Page:Popular Science Monthly Volume 76.djvu/392

388 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.