The twenty-six wards now comprising the city of Brooklyn, contained in 1880 a population of 580,313; if, therefore, their present population as above estimated is 782,221, there has been an increase in eight years of 201,903, or an average annual gain for each of those years of 25,237. But the population in 1870 was 396,099, and in 1875, as enumerated by the State Census, it was 484,616, showing a gain for the five years of 87,518, or an average annually of 17,500. Between 1875 and 1880 it rose to 566,663, the total gain for the five years being 82,047, the average annual gain being 16,400. It should, therefore, first be noticed that the rate of increase of the last decade was more rapid during its first half than during its closing half. The present decade began in a period of more moderate growth than that of some years previous. We may, I think, safely assume that the falling off in the gain between 1875 and 1880 was largely due to the opening of the system of elevated roads in New York City in 1878. Making all necessary allowance for the increase due to the Twenty-sixth Ward, which was not a part of the city in 1880, it is still impossible to believe that the average annual gain of 16,400 which prevailed from 1875 to 1880 could have been abruptly changed to the average annual gain of 25,237 which has prevailed from 1880 to the present time. We must, then, assume that during the years since 1880 the rate of growth of the city has advanced quite materially; and that the average increase of the first three or four years of the present decade may not have been much in excess of the average increase of the five years from 1875 to 1880. A sufficient cause for the change of the rate of growth is furnished in the opening of the Bridge in 1883.