IMPORTANCE OF STATISTICAL IDEAS. 



117 



and Ireland, as well as the senior partner, being taken into account, 

 it cannot be said that there is any falling off in the rate of growth of 

 the population since 1850. For several decades after that, in fact, the 

 rate of growth of the United Kingdom as a whole was diminished 

 enormously by the emigration from Ireland, and the growth since 1860 

 has been at a greater rate than in the thirty years before. There may 

 be new causes at work which will again diminish the rate of growth, 

 but in a broad view they do not make themselves visible owing to the 

 disturbance caused by the Irish emigration. Still the facts as to the 

 United Kingdom as a whole ought not to prevent us from considering 

 the facts respecting England only along with the similar facts respect- 

 ing the United States and Australasia. 



These diminutions in the rate of growth of large populations, as I 

 have indicated, are corroborated by a study of the birth-rates, and of the 

 rate of the excess of births over deaths. 



The United States unfortunately is without birth- or death-rates, 

 owing to the want of a general system of registration over the whole 

 country. This is a most serious defect in the statistical arrangements 

 of that great country, which it may be hoped will be remedied in time. 

 In the absence of the necessary records I have made some calculations so 

 as to obtain a figure which may be provisionally substituted for a proper 

 rate of the excess of births over deaths, which I submit for what it may 

 be worth as an approximation, and an approximation only. In these 

 calculations one-tenth of the increase of population between two census 

 periods, apart from immigration, is compared with the mean of the 

 population at the two census dates themselves, with the following 

 results : 



Approximate Rate of Excess of Births over Deaths in the United States, calcu- 

 lated from a Comparison of One-tenth the Increase of Population between 

 the Census Periods, deducting Immigrants, loith the Mean of the Numbers 

 of the Population at the two Census Dates. 



