We have no accurate statistics of the early operation of American railways. In 1867 Poor’s Manual estimated their total freight tonnage at 75,000,000 and the total freight receipts at $400,000,000. This was an average rate per ton of $5.33. In 1899 Poor gives the total freight tonnage at 975,789,941 tons, and the freight receipts at $922,436,314, or an average rate per ton of ninety-five cents. Had the rates of 1867 prevailed, the additional yearly cost to the public would have been $4,275,000,000, or sufficient to replace the whole railway system in two and a half years. This is an illustration only, but a very striking one. Everybody knows that such high rates of freight as those of 1867 would have checked traffic. This much can surely be said: the reduction in cost of operating our railways, and the consequent fall in freight rates, have been potent factors in enabling the United States to send abroad last year $1,456,000,000 worth of exports and flood the world with our food and manufactured products. BRIDGE BUILDING In early days the building of a bridge was a matter of great ceremony, and it was consecrated to protect it from evil spirits. Its construction was controlled by priests, as the title of the Pope of Rome, “Pontifex Maximus,” indicates. Railways changed all this. Instead of the picturesque stone bridge, whose long line of low arches harmonized with the landscape, there came the straight girder or high truss, ugly indeed, but quickly built, and costing much less. Bridge construction has made greater progress in the United States than abroad. The heavy trains that we have described called for stronger bridges. The large American rolling-stock is not used in England, and but little on the continent of Europe, as the width of tunnels and other obstacles will not allow of it. It is said that there is an average of one bridge for every three miles of railway in the United States, making 63,000 bridges, most of which have been replaced by new and stronger ones during the last twenty years. This demand has brought into existence many bridge-building companies, some of whom make the whole bridge, from the ore to the finished product. Before the advent of railways, highway bridges in America were made of wood, and called trusses. Few of them existed before railways. The large rivers and estuaries were crossed in horse-boats, a trip more dangerous than an Atlantic voyage now is. A few smaller rivers had wooden truss bridges. Although originally invented by Leonardo da Vinci, in the sixteenth century, they were reinvented by American carpenters. Some of Burr’s bridges are still standing after more than one hundred years’ use. This shows what wood can do when not overstrained and protected from weather and fire. The coming of railways required a stronger type of bridge to carry concentrated loads, and the Howe truss, with vertical iron rods, was invented, capable of 150-foot spans.