Page:Popular Science Monthly Volume 48.djvu/267

Rh the first of those decades, 1840 to 1850, the rate was abnormal because the Mexican War brought us a sudden large accession of black and white population from the conquered provinces of Texas, New Mexico, and California. The rate in the second decade, 1850 to 1860, was also abnormal. The people who were not counted in California in the census of 1850, owing to the burning of part of the returns, were counted in 1860, and increased the rate for that decade:

During the last twenty years immigration has reached enormous proportions. For the decade 1870 to 1880 the arrivals at ports, without counting those that came in over the Canadian and Mexican borders, were 2,834,040, and for 1880 to 1890 the same sort of arrivals were 5,246,613. Added together they make for the twenty years 8,080,653, which is more than half of the total immigration since 1820. Yet with this enormous influx the rate of increase of the whole population has sunk lower and lower; and the twenty years which saw this huge immigration saw the lowest rate of increase since 1750.

From the year 1750 to 1830 the native population without the assistance of immigration never increased less than 33·17 per cent each decade except during the Revolution, when it went down to 28·81 per cent. But now, with a larger immigration than was ever known, the increase of our aggregate population is only 24·85—almost 4 per cent lower than the rate of increase of the native whites during the Revolution.

mopane tree of eastern Mashonaland, Africa, is described by W. A. Eckersley, of the railroad surveying party, as rarely attaining a height of more than twenty-five feet. "When first its leaves make their appearance they are bright red; this soon changes to a rich autumnal brown; passing through some further shades of that color, they finally assume a green of equal brilliance to the spring leaves of some of our English trees. Masses of these trees in the various stages of change form a remarkably picturesque effect; the strong contrast in which the brilliant reds and greens stand out against the background of the blue-gray granite is particularly striking."