the species found lower down in the cañons often show a greater affinity to Mexican and Californian types. I was more fortunate than Lieutenant Carpenter, and took over twenty species of butterflies above the timber-line.
I have endeavored to show that sometimes at least insects are quite plentiful in the Colorado mountains. They are certainly more plentiful in the mountain-regions than on the plains.
| Yours very truly, |
| J. Duncan Putnam. |
| Davenport, Iowa, January 10, 1877. |
EFFECTS OF THE WAR ON THE INCREASE OF POPULATION IN THE LAST DECADE.
To the Editor of the Popular Science Monthly.
The Superintendent of the Ninth Census, while showing the causes of loss in population produced by the late war, neglected to point out the actual decrease incident to this cause, as shown by the State censuses of 1865.
The retarding influence may be seen by reference to the States of New York and Massachusetts.
In the former State, whereas the regular increase for each period of five years had been nearly 500,000, from 1860 to 1865 there was a decrease of 29,000. From 1865 to 1870 there was an increase of 529,000.—("Manual" for 1870.)
In Massachusetts the increase of population from 1850 to 1855 was 138,000; from 1855 to 1860 it was 90,000; from 1860 to 1865, 36,000; from 1865 to 1870, 190,000; and from 1870 to 1875, 194,000. The regularity of increase in the State is shown by the fact that the difference between the actual population in 1870 and that computed on the supposition that the increase was in arithmetical progression was only 2,120.—("Massachusetts State Census" for 1875, vol. i., p. xxxii.)
In these two States, therefore, the increase of population during the war-period was only 7,000, while in the next five-year period it was fully a hundred times as great. The population of these two States was over 6,000,000, or more than fifteen per cent, of the total population of the United States.
As it may be urged that these States suffered heavily in loss of immigration, we will attempt to estimate their actual loss in this respect. The total loss of immigration is estimated ("Ninth Census," vol. i., p. xix.) at 350,000. If we suppose the immigration into a State to be proportionate to the foreign population of that State, the proportion of loss in immigration for these two States will be 27 per cent. of the whole loss, or about 94,500. Omitting the loss in immigration, therefore, the total gain of these two States will be 101,500. Even if we further suppose that these States suffered another special loss of 48,500, the total gain would still be only 150,000. Multiplying this by 8, the ratio between the increase of population in these States (700,000) from 1865 to 1870, and the estimated increase of the United States for the same time, we get for the total gain of the country, without considering the loss in immigration, 1,200,000. Deducting this loss, we have for the entire gain 850,000.
We have no reason to suppose that New York and Massachusetts were especial sufferers during this period. Many of the Southern States probably suffered more, especially in loss of negro population, which amounted to half a million during this period ("Ninth Census," vol. i., p. xviii.). There is, then, no reason to suppose that the above estimate falls far short of the truth. Even if the estimate is increased to 1,500,000, which seems improbable, the population of the country in 1865 would still fall short of 33,000,000. This would indicate for the succeeding period of five years an increase of 5,500,000, which is somewhat above the average. That this large increase is actual is rendered probable by the corresponding large increase in Massachusetts and New York for the same time.
