836 



UNITED STATES CENSUS. 



to be located at the center of that degree, except 

 in cases where it was manifest that this assump- 

 tion would be untrue, as, for instance, where a 

 part of the square degree was occupied by the 

 sea or other large body of water, or where it con- 

 tained a city of considerable magnitude which 

 was situated ' off center.' In these cases the po- 

 sition of the center of the population of the 

 square degree was estimated as nearly as pos- 

 sible. The distance of each such center of popu- 

 lation of a square degree, whether assumed to be 

 at the center of the square degree or at a distance 

 from the center, from the assumed parallel, and 

 from the assumed meridian were then computed. 

 The population of each square degree was then 

 multiplied by its distance from the assumed par- 

 allel of latitude, and the sum of the products or 

 moments north and south of that parallel made 

 up. Their difference, divided by the total popu- 

 lation of the country, gave a correction to the 

 latitude. In a similar manner the east and west 

 moments were made up, and from them a cor- 

 rection in longitude was obtained." 



During the ten years terminating with 1800 

 the center of population moved 41 miles almost 

 due west, starting from a point about 28 miles 

 east of Baltimore. From 1800 to 1810 the move 

 was 36 miles westward and slightly southward ; 

 1810 to 1820, 50 miles westward and slightly 

 southward ; 1820 to 1830, 39 miles westward and 

 southward; 1830 to 1840, 55 miles westward and 

 and northward; 1840 to 1850, 55 miles westward 

 and slightly southward ; 1850 to 1860, 81 miles 

 westward and slightly northward ; 1860 to 1870, 

 42 miles westward and sharply northward, reach- 

 ing a point about 48 miles east by north of Cin- 



cinnati, Ohio, and in 1880 the center of popula- 

 tion had moved 58 miles to a point 8 miles west 

 by south of the same city. From 1880 to 1890 

 it moved westward 48 miles. 



Distribution in Accordance with Rain- 

 fall. The average rainfall in the United States 

 is 29-6, the variations ranging from to about 

 125 inches. The larger number of the inhab- 

 itants occupy the region in which the annual 

 rainfall is between 30 and 50 inches, comprising 

 about three fourths of the entire population, 

 while the greatest density of population is in the 

 area showing 40 to 50 inches of annual rainfall, 

 the average of this region being 59 inhabitants 

 to the square mile. In the eastern portions of 

 the Great Plains stretching from Texas to Da- 

 kota, where the most rapid increase in popula- 

 tion is taking place, the rainfall ranges from 20 

 to 30 inches. The density of population in this 

 section has increased in twenty years from 1'6 to 

 8'1 per square mile. In every 100,000 of the pop- 

 ulation, 300 are living in a region where the rain- 

 fall is below 10 inches. Where the rainfall is 

 from 10 to 20 inches, the population is 2,612 in 

 every 100,000 ; from 20 to 30 inches, 6,038 ; 30 to 

 40 inches, 34,107 ; 40 to 50 inches, 39,459 ; 50 to 

 60 inches, 16,164; 60 to 70 inches, 1,274; and 

 above 70 inches of rainfall the population is 

 equal to 55 in every 100,000. The average rain- 

 fall with relation to the population, deduced by 

 giving weight to each area of country in propor- 

 tion to the number of inhabitants, is 41 '4 inches. 

 In 1880 it was 42 inches, and in 1870 42-5 inches. 

 The diminution has been caused mainly by the 

 settlement of the Great Plains and the arid re- 

 gions of the West. 



* Includes 4,229 tons of castings made direct from furnace. t Includes 9,929 tons of castings made direct from furnace. 

 $ Each Bessemer, open-hearth, and crucible steel plant is counted as separate works, although two or more of these plants 

 are frequently embraced in a single establishment. 



