years ago that the burning of a sheet of paper would move a ton a mile. =361. Resulting decline in freight rates.=—Even in 1884 a competent writer could make this interesting statement: twenty years before, a steamer of 3,000 tons had to allow for coal and machinery on a given voyage 2,200 tons, and must confine the cargo to the remaining space; at the date when he wrote the great improvements had reversed the proportions, so that only 800 tons were needed for motive power and 2,200 were devoted to cargo. Manifestly steamship owners would be enabled by a change of this character to lower greatly the charges for transportation, and freight rates have, in fact, declined steadily in the course of the century. Lancashire spinners could transport their raw cotton from the source of supply in America at one sixteenth the cost which they had to bear sixty years before. Even in the last quarter of the century ocean freight rates dropped to one half, one third, or even one fourth, of the figures prevailing in 1874. Conditions such as have been thus briefly suggested explain the immense increase in sea-borne traffic during the century. For the carriage of that traffic the merchant has now at his disposal not only the sailing ship and the “tramp,” the general-utility steamer, but also a multitude of special boats for special services: the tank-steamer for transporting liquids cheaply, the cattle steamer for live stock, and the steamer with refrigerators for dead meat, the fruit steamer, etc. The use of oil as fuel and the introduction of explosion motors of the Diesel type promise to raise still higher the efficiency of transportation. =362. Modern ship canals.=—This survey of the development of the means of navigation may fitly be closed by a brief consideration of the modern ship canals and their contribution to the growth of trade. There were, in 1900, a round dozen of these canals, capable of receiving sea-going ships. Some, serving special ports (Amsterdam, Manchester, etc.) were of purely local importance. Others have disappointed the expectations of their promoters. The canal across the isthmus of Corinth has been a distinct failure, and the Kaiser Wilhelm Canal, between the North and Baltic seas, has not yet acquired the share of commerce which its projectors promised for it. Leaving aside the St. Mary’s canal in America there was up to 1914 but one ship canal which had proved its commanding importance, namely the Suez Canal.