by the roads during the ensuing interval between the reduction of rates during the seventies and the mechanical improvements of the succeeding decade. An incidental result of the rate wars of this period, it may also be noted, was the readjustment of the relative shares of the great seaports in foreign business. Philadelphia, especially, increased its quota of exports from about eleven per cent, in 1860 to over twenty per cent. in 1880. Much of this was gained, however, from the southern ports, as the relative status of Baltimore, New York, and Boston remained about the same. A second important consequence of the severe decline in railroad rates during the seventies, was the permanent supersession of canals and riverways in favor of railroads as means of transportation. The Erie Canal outlasted all the other artificial water routes, most of which had succumbed to rail competition by the close of the Civil War. But even as late as 1868, practically all of the grain arriving at New York came by canal. The change, when it occurred, came suddenly. [Illustration: FREIGHT RECEIPTS AT NEW YORK] No canal could meet the fierce slashing of rates which suddenly supervened on the rail lines. Since 1855, when the canal carried twice the traffic of all the trunk lines, until 1861-1862 when the rail and water lines were about even, the railroads had steadily gained in tonnage.[16] The turning point was reached in 1872 when the canal traffic actually began to decline. Between 1871 and 1876 the aggregate tonnage (both ways) on the New York canals fell away about half, spasmodically recovered during the great expansion of exports in 1879-1880, held constant for five years, and thereafter steadily dwindled away. As the accompanying diagram shows, the rise of railroad tonnage was rapid up to 1873. Thereafter for several years during the actual panic, despite the railroad wars and low rates, no great change occurred. But by 1876, eighty-three per cent. of all-grain receipts at Atlantic ports came by rail; and over nine-tenths of all the commerce between East and West had left the water routes. At New York the three main railroads carried six times the traffic of all the state canals in 1880. After that time the canal barges were loaded only with coal, lime, sand, cement, and similar low-grade traffic. So that in the rapid expansion of business, which, as our diagram shows, occurred after 1878, the canal shared not at all. The disparity between east-and westbound tonnage was notably great. In 1870 this eastbound traffic was about three times as great as the tonnage west bound. In 1881 it was seven and one-half times as great, declining thereafter to a proportion of about 6.5 to 1 during the late nineties. This inequality, of course, whetted the appetite of the carriers for back loads to fill the westbound trains, and undoubtedly gave an impetus to rate disturbance. The rate wars led by the New York Central during 1881 were largely due to this fact.