One of the largest of these steamers was the Grand Republic,[96] a vessel 340 feet long, 56 feet beam, and 101∕4 feet depth. The draught of water of this great craft was 31∕2 feet forward and 41∕2 aft. The two sets of compound engines, 28 and 56 inches diameter and of 10 feet stroke, drive wheels 381∕2 feet in diameter and 18 feet wide. The boilers were steel. A steamer built still later on the Ohio has the following dimensions: Length, 225 feet; breadth, 351∕2 feet; depth, 5 feet; cylinders, 173∕8 inches in diameter, 6 feet stroke; three boilers. The hull and cabin were built at Jeffersonville, Ind. She has 40 large state-rooms. The cost of the steamer was $40,000.
These vessels have now opened to commerce the whole extent of the great Mississippi basin, transporting a large share of the products of a section of country measuring a million and a half square miles—an area equal to many times that of New York State, and twelve times that of the island of Great Britain—an area exceeding that of the whole of Europe, exclusive of Russia and Turkey, and capable, if as thoroughly cultivated as the Netherlands, of supporting a population of between three and four hundred millions of people.
The steam-engine and propelling apparatus of the modern ocean-steamer have now become almost exclusively the compound or double-cylinder engine, driving the screw. The form and the location of the machinery in the vessel vary with the size and character of the ship which it drives. Very small boats are fitted with machinery of quite a different kind from that built for large steamers, and war-vessels have usually been supplied with engines of a design radically different from that adopted for merchant-steamers.
Fig. 134.—Steam-Launch, New York Steam-Power Company.
The introduction of [Steam-Launches] and small pleasure-boats driven by steam-power is of comparatively recent date, but their use is rapidly increasing. Those first built were heavy, slow, and complicated; but, profiting by experience, light and graceful boats are now built, of remarkable swiftness, and having such improved and simplified machinery that they require little fuel and can be easily managed. Such boats have strong, carefully-modeled hulls, light and strong boilers, capable of making a large amount of dry steam with little fuel, and a light, quick-running engine, working without shake or jar, and using steam economically.
Fig. 135.—Launch-Engine.