The first successful steamboat for commerce was, as is well known, Robert Fulton's flat-bottomed side-wheeler _Clermont_, which in August, 1807, made the 150 miles from New York to Albany in 32 hours. During the war of 1812 Fulton designed for coast defense a heavily timbered, double-ender floating battery, with a single paddle-wheel located inside amidships. On her trial trip in 1815 this first steam man-of-war, the U. S. S. _Fulton_, carried 26 guns and made over 6 knots, but she was then laid up and was destroyed a few years later by fire. Ericsson's successful application of the screw propeller in 1837 made steam propulsion more feasible for battleships by clearing the decks and eliminating the clumsy and exposed side-wheels. The first American screw warship was the U. S. S. _Princeton_, of 1843, but every ship in the American Navy at the outbreak of the Civil War had at least auxiliary sail rig. Though by 1850 England had 30 vessels with auxiliary steam, the _Devastation_ of 1869 was the first in the British service to use steam exclusively. Long after this time old "floating museums" with sail rig and smoothbores were retained in most navies for motives of economy, and even the first ships of the American "White Squadron" were encumbered with sails and spars. [Illustration: EARLY IRONCLADS] Progress in ordnance began about 1822, when explosive shells, hitherto used only in mortars, were first adopted for ordinary cannon with horizontal fire. At the time of the Crimean War shells were the usual ammunition for lower tier guns, and at Sinope in 1853 their smashing effect against wooden hulls was demonstrated when a Russian squadron destroyed some Turkish vessels which fired only solid shot. The great professional cry of the time, we are told, became "For God's sake, keep out the shell."[1] [Footnote 1: Custance, THE SHIP OF THE LINE IN BATTLE, p. 9.] In 1851 Minie rifles supplanted in the British army the old smoothbore musket or "Brown Bess," with which at ranges above 200 yards it was difficult to hit a target 11 feet square. This change led quickly to the rifling of heavy ordnance as well. The first Armstrong rifles of 1858--named after their inventor, Sir William Armstrong, head of the Royal Gun Factory at Woolwich--included guns up to 7-inch diameter of bore. The American navy, however, depended chiefly on smoothbores throughout the Civil War. Breech-loading, which had been used centuries earlier, came in again with these first rifles, but after 1865 the British navy went back to muzzle-loading and stuck to it persistently for the next 15 years. By that time the breech-loading mechanism had been simplified, and its adoption became necessary to secure greater length of gun barrel, increased rapidity of fire, and better protection for gun-crews. About 1880 quick-fire guns of from 3 to 6 inches, firing 12 or 15 shots a minute, were mounted in secondary batteries.