The geographical distribution of railway mileage, at successive periods, throws light upon various stages of industrial development. In 1840, 88.92 per cent. of the total railway mileage of the United States was in the States bordering on the Atlantic Ocean, north of the Savannah River, and in Pennsylvania and Vermont; by 1850 this percentage had decreased to 73.23; by 1860, to 42.49; by 1870, to 35.21; by 1880, to 28.27; by 1890, to 21.10; and in 1898 it was 21.49. In 1840 the States of Ohio and Indiana, the lower peninsula of Michigan, and those portions of New York and Pennsylvania which lie west of Buffalo and Pittsburgh had but 197.76 miles of railway or 7.18 per cent. of the total then in the country; in 1850 this region contained 11.88 per cent. of the total; in 1860, 20.52 per cent.; in 1870, 16.92 per cent.; in 1880, 16.31 per cent.; in 1890, 13.27 per cent.; and in 1898, 12.39 per cent. The relative decrease shown after 1860 is due to the rapid increase in mileage in the region west of the Great Lakes and the Mississippi River. The region that includes the States of Georgia, Florida, Alabama, Mississippi, Tennessee and Kentucky had 86.75 miles of railway in 1840, being 3.15 per cent. of the total mileage of the United States at that time. Ten years later this region contained 13.11 per cent. of the total; in 1860, 18.18 per cent.; in 1870, 15.45 per cent.; in 1880, 9.77 per cent.; in 1890, 11.39 per cent.; and in 1898, 11.74 per cent. The relative decrease in the twenty years after 1860 is explained partly by the rapid development of the region west of the Mississippi River, during those decades, and partly by the exhaustion following the Civil War. The comparative acceleration of construction after 1880 is attributable to the development of the mineral resources of the States in this region. Passing westward to the region between the Great Lakes, the Illinois-Indiana State line, the Missouri River, and the Canadian frontier, it is found that this region contained no railways in 1840 and but one hundred and seven miles of line, or 1.25 per cent. of the total, in 1850. By 1860 the percentage had risen to 15.15; by 1870, to 19.74; by 1880, to 25.62. The exceedingly rapid construction in the region still farther west, during the ten years ending in 1890, resulted in a decrease to 22.90 per cent., though the railways in the region were increased

In 1898 the percentage for

by nearly 15,000 miles of new line. this region was 22.17. In 1840 the entire territory west of the Mississippi and Missouri had but 20.75 miles of railway, which were located in the State of Louisiana, and in the next decade this was little more than doubled by the construction of a second line in the same State, which made the aggregate in 1850, 46.48 miles, or but little more than one-half of one per cent. of the mileage then existing in the country. Even as late as 1860 this region had but 3.67 per cent. of the railway mileage of the United States. In 1870 the percentage was 12.68; in 1880, 20.03; in 1890, 31.33; and in 1898, 32.21. The latter region includes 62.71 per cent. of the total area of the United States, and in 1890 it contained 18.58 per cent. of the total population.

The early railways were so far inferior to those now in existence that comparisons are scarcely practicable. The ordinary superstructure at first adopted was a longitudinal wooden sill upon which was laid a strap or rail of iron, the purpose of the latter being to prevent abrasion of the wood rather than to bear the weight of the train. The change from wood to iron, as the principal portion of the track, was very gradual, and it was not until about 1850 that the longitudinal sill and flat rail was superseded even on the Utica and Schenectady Railroad, one of the most important links in the New York Central system. Following the change from wood to iron came the substitution of steel for iron. The manufacture of steel rails, in commercial quantities, began in the United States in the year 1867, but they were used by railways experimentally only until several years later. The following table shows the number of miles of track, including sidings, yard track, second track, etc., the mileage of steel track and the proportion of the latter to the former, in various years, beginning with 1880:

The same period which has witnessed the general adoption of steel rails has been characterized also by a gradual increase in the weight of the rails used. Starting with steel rails, weighing from fifty to sixty pounds per yard, the movement has gone on by successive steps until at the present time long sections of track weighing one hundred pounds per yard are by no means uncommon. During the same period there has been a general straightening of track wherever practicable, a lengthening of the radii of curves, where the latter are unavoidable, and a grading down of the steeper inclines. With the improvement of track there has also been a steady development of the train as a machine for moving traffic. Locomotives have been greatly increased in weight and power, and are thus able to draw longer trains composed of larger cars. The ten, twelve, and fifteen ton freight cars, that were, themselves, far more capacious than those which they superseded, have disappeared or remain as interesting relics of transportation methods that are fast disappearing. The minimum capacity of a modern freight car is about thirty tons, cars of forty tons capacity are much more common, and orders for those able to carry 100,000 pounds of paying freight are frequent. The substitution of steel for wood, as the principal material for freight cars, which is now commencing, promises rapidly to increase the average efficiency of freight equipment by decreasing the proportion of dead weight to be moved. Some consequences of these changes in the physical characteristics of railways and railway equipment are indicated by the following table:

The significant fact shown in the foregoing table, that the average number of miles run by freight trains per mile of road operated has actually decreased while the average number of tons carried one mile has more than doubled, is the consequence of the improvements in roadway and equipment, which have permitted the train load to be increased from 81.72 tons to 226.45 tons, or 177.10 per cent.

No incident of the development of railway transportation is more significant than the continuously progressive movement toward the coördination of the legally separate and independent corporate units that compose the railway system. Whenever any thought of such coördination occurred to those who constructed railways during the first half of the period of American railway development, they appear deliberately to have tried to make it impracticable. One of the devices most frequently resorted to was to make necessary the interruption of the process of transportation, and the transfer of traffic from car to car, and giving employment, at unnecessary labor, to local residents, by constructing connecting lines with different gauges. At least four gauges were formerly in use on roads of considerable length, but these have all been practically superseded by the standard gauge, which varies from four feet eight and one-half inches to four feet nine inches. A few short and unimportant roads still retain the narrow, or three feet gauge, but the six feet or broad gauge, and the five feet gauge, which formerly prevailed throughout all the cotton States, have entirely disappeared.

Through passenger car lines, tickets for the transportation of passengers over two or more lines, through way-bills for freight, and the interchange of freight cars are all important steps in the process of coördination. This process has been materially advanced by numerous associations, for conference and discussion, formed by the officers in charge of special phases of railroad work. These associations are now very numerous and it would be difficult to overestimate the value of their services in increasing the efficiency of the facilities that are operated under the direction of those who compose them.

There has also been a very definite contribution to railway efficiency through the unification of the operating machinery of short connecting lines, and the formation of much more extensive systems than were contemplated by early railway builders. This welding of formerly independent lines has been accomplished by the lease of the property of one corporation by another; by the purchase of controlling interests in separate corporations, by the same individual or by a compact group of individuals; and, in other instances, perhaps more numerous than either, by the actual merger of two or more corporations.

The New York Central and Hudson River Railroad, the Pennsylvania system, and the Atchison, Topeka and Sante Fé Railroad, are prominent examples of the results of this welding process. The main line of the first named road was constructed, and for a time operated, by eleven companies, ten of which, forming the line from Albany to Buffalo, were consolidated as the New York Central Railroad in 1853; the line from New York to Albany, which had been independently operated for eighteen years, being added in 1869. The New York and Harlem Railroad, a parallel line for part of the distance, was added in 1873.

The following table shows the progress of this form of unification as far as it can be traced statistically, but does not include those practical consolidations which have not affected the operating organizations. The data for 1892, 1896, and 1898 are from the reports of the Statistician to the Interstate Commerce Commission, and are substantially complete. Those for 1867 represent 46.61 per cent.; for 1872, 68.40 per cent.; for 1877, 87.32 per cent.; for 1882, 89.94 per cent.; and for 1887, 87.81 per cent. of the entire railway mileage in operation. It is probable that the inclusion of all roads, had it been practicable, would have increased the proportions in the classes embracing the shorter lines. In other words, the table does not show the full relative increase of mileage operated by the more important corporations. The changes which have increased the efficiency of railway facilities have been, in some degree at least, expressed in the form of reductions in the charges for the use of those facilities. An elaborate investigation of the rates of charge for railway and other transportation services was recently conducted under the