that such a rate of national growth will continue. Its continuance for so long a period would involve an increase of over forty millions (40,000,000) between 1920 and 1930, and over fifty-five millions (55,000,000) between 1930 and 1940. It seems more reasonable to expect a gradual decline in the rate of increase, and that the relation between this country and Europe will more closely approach an equilibrium, accompanied or followed by a diminution of the force of immigration as a factor in our national growth. Immigration in the past has fluctuated widely. The total number of immigrants landing in this country for the whole decade closing in 1880, was less than that for the first five years of the present decade. To what degree the population of the future will dwell in cities can perhaps best be foretold by present indications in our own land, or by the conditions prevailing in more thickly settled nations. Present indications here, as has been pointed out, suggest a city growth more rapid than that of the remainder of the population. Among the older nations, the population of the British Isles may be said to resemble our own most closely. The population of Great Britain and Ireland in 1881 was thirty-five millions (35,000,000). More than one-tenth of this population was contained in London alone. Such an urban population manifestly sustains itself largely if not chiefly upon the commercial and maritime importance of the nation containing it, and only to a minor degree upon the community surrounding it. This condition of existence may never be as emphatically true of the population about the port of New York as it is of the population of London, yet it has always been believed that the final commercial position of our nation must be one of commanding importance. That belief compels the inference that the great port of the nation and of the continent must continue to attract an enormous population. That the present rate of growth, which adds 30 per cent. to the population of New York, and more than 40 per cent. to that of Brooklyn, in every ten years, will endure, need not be expected. The results of a computation upon such a basis seem incredible, since they call for a population of three million five hundred thousand (3,500,000) in New York in 1920, and of two million two hundred thousand (2,200,000) in Brooklyn at the same time. But we may well believe that in the nation there will be a gradual approach to the density of population now maintained in older countries; that this port will hold its place as a general point of concentration and distribution for the nation, the continent, perhaps for the world; and that the excess of residence area in and about our own city over the corresponding area of New York must continue to tell in our favor, probably with increasing force. Looking back no further than 1850, and comparing the two cities with each other, the following table shows their numbers and rate of growth in the successive decades: