Substantially the same thing is to be observed in the statistics of important metal mining companies, which function in a highly mechanicalized industry, perhaps the most perfectly mechanicalized of any. Also in the railway statistics something of the same order is discernible. Data of railway traffic are given in the following tables:
| Year | Tons of original freight | Net ton miles | Passenger miles | Transportation service train miles |
| 1916 | 1,203,367,190 | 396,365,917,082 | 34,585,952,026 | 1,224,168,566 |
| 1917 | 1,264,015,725 | 430,319,014,635 | 39,476,858,549 | 1,237,137,632 |
| 1918 | 1,263,343,993 | 440,001,713,665 | 42,676,579,199 | 1,175,782,791 |
| 1919 | 1,096,111,271 | 395,679,051,729 | 46,358,303,740 | 1,117,547,908 |
| 1920 | 1,255,420,991 | 449,125,000,000 | 46,847,534,000 | 1,190,444,000 |
| 1921 | 940,182,560 | 344,911,000,000 | 37,338,959,000 | 1,075,451,000 |
| 1922 | 1,023,109,578 | 375,617,000,000 | 35,507,222,000 | 1,085,751,000 |
Railway traffic in terms of ton-miles, if represented by 294 in 1913, was 338 in 1922. We have been constrained, or led, or both, to move our freight a greater distance during the last few years. For a series of years previous to 1915 the average haul was steadily about 154 miles. Beginning in 1915 there was an increase and in 1920 the figure had risen to 181 miles, the average for 1921 being about the same. The causes for this are not well understood, but anyway it is not to be construed as a favorable economic factor. However, the railways were operated by about the same number of men in 1921 as on the average just before 1915. The ability of the railways to do more work without increase in personnel is wholly ascribable to managerial improvements, for the efficiency of labor has
