In the turbine, with its combinations, it is believed that the steam-engine reaches its highest possible efficiency, just as sails reached their highest efficiency as used on the American clipper. But a new machine, still more economical, has been invented--the gas motor. Coal is used for the generation of gas, which drives internal-combustion motors, much like those seen on automobiles. The consumption of fuel is thereby reduced far below that of steam engines. While the marine steam-engine has been perfected in Europe, it is worth noting by the way that the producer-gas engine, though yet in the experimental stage for ship use, has been brought to a higher state of perfection for land use in America than in Europe. Magazine articles by marine engineers have been published, urging American ship-owners to adopt this new method of propulsion, because it is to make a revolution almost as far-reaching as the iron screw steamer made in 1855. But the American ship-owner refuses to see his opportunity. Having certain profits with old-style engines in the coasting trade, he is willing to let foreigners do the experimenting. All of this is to say that the ship-owners of foreign countries are at least as far-sighted and enterprising as those of the United States. Some of the facts in the story of our coasting steamer trade are of interest in this point of view. The most interesting division of this fleet is found upon the Great Lakes. The screw propeller and the compound engine were successfully introduced on the Great Lakes before 1850--several years before the iron screw steamer of the British began its deadly inroads upon our salt-water trade--but the Atlantic coast remained indifferent. After the Civil War tugs came into use for towing the sailing vessels through the Detroit and Huron rivers, and from these the use of barges in "strings" behind steamers that carried cargoes as well as served as tugs, was developed. This system ruled upon the lakes until the evolution of the iron ore trade led to the building of ships so large that they were unable to handle barges. In 1902 the ship able to carry 10,000 tons arrived. Still larger ships have been built since 1902. A ship that can carry 12,000 tons' dead weight needs but thirty-five men, all told. The average cost of carrying freight on the best ships of the lakes is less than .8 of a mill per ton-mile. Through natural development this splendid efficiency has been attained, and the fleet in 1908 numbered 1942 ships measuring 2,341,686 tons. [Illustration: Seven-masted Schooner _THOMAS LAWSON_]