The Princeton was followed closely by the Rattler, the first screw vessel of the British fleet, and in 1843–44 the French 44-gun frigate Pomone was fitted with propellers. In 1843, also, the English Penelope was the first man-of-war to be equipped with tubular boilers, and the year 1845 was notable for the building of the ill-fated Birkenhead, the first iron vessel of the British fleet. In 1850, when the French constructed the screw line-of-battle ship Napoleon, the English became alarmed, and began with vigor the renovation of their navy with regard to screw propulsion. France, in 1854, laid the keels of four armored batteries, three of which, forming the first ironclad squadron in history, went into action a year later under the forts of Kinburn in the Crimea. They were of 1600 tons’ displacement, carried 4⅓ inch armor and sixteen 68-pdr. guns, and had a speed of four knots. In 1862, Ericsson launched the famous Monitor, the first sea-going ironclad with a revolving turret, and an “engineers’ ship” from keel to turret top. [Illustration: THE TURBINIA.] The Civil War found us with a sailing navy, and left us one of steam. Passing over its victories, in which steamers played always the chief part on sea and river, we come to that most notable triumph of Chief Engineer Isherwood, the cruiser Wampanoag of 4200 tons’ displacement. This vessel, phenomenal in her day, steamed in February, 1868, from Barnegat to Savannah, over a stormy sea, in 38 hours. Her average was 16.6 knots for the run, and 17 knots during a period of six consecutive hours—a speed which for 11 years thereafter was unapproached by liner or by warship. In 1879, the British despatch vessel Mercury, of 3730 tons and 18.87 knots, wrested the palm from America; but, in 1893, it was won again for the United States by the triple-screw fliers Columbia and Minneapolis of 7475 tons, with speeds respectively of 22.8 and 23.073 knots. The laurels rest now with the Buenos Ayres, which, though built in England in 1895, flies the flag of Argentina. She has a tonnage of 4500 and a speed of 23.202 knots. [Illustration: ENGINE OF U.S.S.POWHATAN. A.D. 1849. PLATE III.]