The questions arising from the relations of the railroads to those who use them are wider and older. From the very outset attempts were made to regulate railroad charges by law in various ways. The fear at that time was that they might be made unreasonably high. This fear proved groundless. From the outset the rates were rather lower than had been expected, and much lower than by many of the means of transportation which railroads superseded. These low rates caused a great development in business; and this, in turn, gave a chance for such economy in handling it that rates went still lower. Each new invention rendered it easier to do a large business at cheap rates. The substitution of steel rails for iron, which began shortly after the close of the war, had an enormous influence in this respect. This was not merely due to the direct saving in repairs, which, though appreciable, was moderate in amount. It was due still more to improvements in transportation which followed. It was found that steel rails would bear heavier rolling-stock. Instead of building ten-ton cars to carry ten tons of cargo, companies built twelve-ton cars to carry twenty tons of cargo, or fourteen-ton cars to carry thirty tons; and they made the locomotives heavy enough to handle correspondingly larger trains. A given amount of fuel was made to haul more weight; and of the weight thus hauled, the freight formed a constantly increasing proportion as compared with the rolling-stock itself. The system of rates was adopted to meet the new requirements. Charges were made incredibly low in order to fill cars that would otherwise go empty, or to use the road as nearly as possible to its full capacity. In the twenty years following the introduction of steel rails the traffic of the New York Central increased from less than 400,000,000 ton-miles to decidedly over 2,000,000,000; while the average rates fell from 3.09 cents per ton per mile in 1866 to 0.76 cent in 1886. This is but a single instance of a process which has gone on all over the country. The average freight charge on all railroads of the country to-day is a little over one cent per ton a mile: less than half what would have been deemed possible on any railroad a few years ago.