374 THE POPULAR SCIENCE MONTHLY, 



1,000 feet above the level of the sea, and below 5,000 feet altitude 

 nearly ninety-nine per cent of tlie inhabitants of the country find 

 their residence. At great altitudes but few people are perma- 

 nently residing. One sixth of the people live less than 100 feet 

 above the sea-level. These, of course, reside along the seaboard 

 and in the swamp and level regions of the South. Those living 

 between 2,000 and 2,500 feet above the level of the sea are found 

 largely on the slope of the great Western plains. Mr. Gannett 

 finds that between 4,000 and 5,000 feet above the sea, but more 

 especially between 5,000 and 6,000 feet, the population is greatly in 

 excess of the grade or grades below it; and he attributes this 

 appearance to the fact that the densest settlement at high alti- 

 tudes in the Cordilleran region is at the eastern base of the Rocky 

 Mountains and in the valleys about Great Salt Lake, which 

 regions lie between 4,000 and 0,000 feet elevation. In this great 

 region the extensive settlements at the base of the mountains in 

 Colorado are to be found between 5,000 and G,000 feet above the 

 level of the sea. The mining operations above 6,000 feet, being 

 restricted to the Cordilleran region, largely located in Colorado, 

 New Mexico, Nevada, and California, account for the existence of 

 the population at the altitude of 6,000 feet and more. 



The population of the country is increasing numerically in 

 all altitudes, but the relative movement is toward the region of 

 greater altitudes, and is more clearly perceptible in the regions 

 lying between 1,000 and 6,000 feet above the sea. The population 

 is densest along the seaboard, the narrow strip containing our 

 great seaports, as might be supposed ; but the density diminishes, 

 not only gradually but quite uniformly, up to 2,000 feet, when 

 sparsity of population is the rule. 



If we examine the population relative to latitude and longitude, 

 it will be found that within those degrees in which are located the 

 great cities the greatest density of population occurs, as, for 

 instance, the area between 40° and 41° and longitudes 73° and 75°, 

 containing the great cities of New York, Brooklyn, and Jersey 

 City, with an aggregate population of 3,653,000 inhabitants ; the 

 single square degree between latitudes 42° and 43° and longitudes 

 71° and 72° degrees contains Boston and its suburbs, with 1,233,000 

 inhabitants, and that square between latitudes 39° and 40° and 

 longitudes 75° and 76° holds Philadelphia, with 1,414,000 people. 

 The square of latitudes 41° and 42° and longitudes 87° and 88°, 

 which contains the larger portion of Chicago, has a population 

 of 950,000. It is difficult to present the facts relative to the dis- 

 tribution of population in accordance with latitude and longitude 

 for the whole country in this summary statement of salient points. 



The distribution of population relative to mean annual rain- 

 fall indicates not only the tendency of people to seek arable lands. 



