August i6, 1889.] 



SCIENCE. 



115 



The following table shows the rate of increase since 1790, as shown 

 by the census returns : — 



The mean of the rates is 33.46 per cent. If we substitute for 

 22.6 (the exceptional rate of the increase between 1S60 and 1870) 

 34.8 per cent (a mean between the rates immediatelj' preceding 

 and following the decennial epoch), we find as probable rates of 

 increase and aggregates of population, had peace continued, the 

 following : — 



This is 9,860,000 more than the population actually to be expected 

 in the next census, — loss to be attributed to a great war. Other 

 variations in the decennial rate of increase are due to the war of 

 181 2, the Mexican war, the cholera epidemics, etc., and to emigration. 

 In estimating the progress of population during another century, 

 it is not perhaps rash to assume a rate of 33.3 per cent, which is a 

 little less than the mean rate, including war and pestilence, which 

 has ruled our growth in the last century. Adding one-third to 

 each decennial estimate, we find the probable population to be as 

 follows : — 



904,921,686 

 [,206,562,248 



This completes the century. Then, as the area of the territory 

 of the United States is 3,026,494 square miles, the density of its 

 population in 1990 will be 399 to the square mile. The density of 

 population in certain countries is given in the same cyclopsedia (printed 

 in 1S78) as follows : United States, 12.7 per square mile ; Atlantic 

 States, 46.6; basin of the Ohio, 37.7 ; Massachusetts, 201 ; Ohio, 66 ; 

 Belgium, 434; China, 420 ; England, 3S9; Europe, 71 ; Asia, 46 ; 

 Africa, 16; America, 6 ; Australia,^. Such a nation will have a 

 power and a commerce and industry not heretofore known to the 

 world. Our ships and those of our allies will bring the spare 

 products of every land to our shores. Systems of interior land and 



water transport, perhaps mostly operated by electric power, will 

 rapidly and cheaply distribute them. 



For a century we may hope to live comfortably and abundantly 

 -within our boundaries. But other people must grow also. The 

 now empty and waste places of the earth will be occupied by 

 civilized and industrious nations. We have in this generation made 

 wonderful and rapid progress in the discoveries and inventions of 

 science. We use the electric force, as did our fathers that of 

 steam. In all probability, electricity will heat as well as light our 

 houses, and will cook our food. It will drive other as well as our 

 city passenger railroads. And it is not probable that man has yet 

 discovered all the resources laid up by the Creator to be discovered 

 and utilized by his creatures when needed for their happiness and 

 comfort. 



The Anglo-Saxon race will occupy the continent from the Isth- 

 mus to the Arctic, and, when crowded therein, must spread over 

 South America, or perish. That they are not likely to submit to 

 As the prairie wolf disappears when man drives off or subjugates 

 the aiiimals on which he lives, and for whose regulation he appears 

 to have been created, so will the weaker races give way to the 

 stronger. It has been thus in all history, and the law still holds. 

 There are in the United States a majority of whites over blacks of 

 51,000,000. They will be able to settle without bloodshed most of 

 the apparently troublesome questions as to races, as may to them 

 seem best ; and when they agree upon the methods, and necessity 

 enforces the duty, they will settle them for the best good of the 

 greatest number. 



Soon after the civil war it was often said that they who believed 

 in the success of the United States, and conducted their affairs on 

 the theory of such success, grew rich and prospered. They who 

 took the opposite belief were unsuccessful, and lost their fortunes. 

 Those who believe in the prospects here set forth will rule their 

 undertakings and investments in the expectation that property in 

 real estate must advance in the next half-century ; that commerce 

 and transportation and production must increase enormously. As 

 the discoveries and inventions of science and industry make towns 

 more and more healthful, convenient, interesting, and agreeable 

 places of residence, our people will tend more and more toward 

 them. Museums, libraries, public halls for the education and in- 

 struction and amusement of the people, will be more and more 

 numerous and cheap. The streets and parks will be embellished 

 and made gay with public and private buildings. Electric engines 

 will do the heavy work of the day. More time will be at the disposal 

 of men for enjoyment, as these improvements relieve men and 

 women from slavish toil for the means of living. 



It may be assumed that the cities will grow at least as fast as the 

 country. In 1790 the urban population was estimated at one- 

 thirtieth the whole; in 1S40, at one-twelfth ; and in 1870, at one- 

 fifth. In 1990 the urban population will be 240,000.000 ; and of these. 

 New York will probably contain over 30,000,000. What will be 

 the value of lands in that city then, may be inferred from the auc- 

 tion-sales of London, which has 4,000,000 people. But there is 

 here an inexhaustible field for investigation and speculation. We 

 leave it to others to explore, having fulfilled the task we set our- 

 selves, of calling the attention of those who inaugurate or direct 

 great enterprises to the need of looking, in arrangements for the 

 future, to a longer period than the decennial census, which is the 

 limit of all speculations on the subject of population and growth 

 which I remember to have seen in print. Twelve hundred millions 

 of intelligent, educated, industrious people, of one race and blood, 

 under one free government, armed with all that science teaches 

 and man has invented — who will wish to interfere with their hap- 

 piness .' Who will attack them .-' 



The probable increase in the ten years from 1930 to 1940 will be 

 about 68.000,000. This is equivalent to 13.600,000 families. Con- 

 sidering only the building trades, this will require the construction 

 in ten years of 14,000,000 new domiciles or family residences. 

 Each will need as much floor and window area as now. Does any 

 one yet foresee the volume of business and its activitj', in construct- 

 ing within a single decade as many buildings as at this time exist 

 within the limits of the United States ? 



What work for architects, contractors, builders, carpenters, 

 masons, brick-layers, plasterers, brick-makers, quarriers, saw-mills. 



