Length 174 ft. 10½ ins. Beam 43 ft. 6 in. Mean Draught 20 ft. 0 in. Displacement 2200 tons. WILLIAM DOUGHTY, Fecit. 1796, Oct. Joshua Humphreys, of Philadelphia, Designer. Cloghorne and Hartley, of Boston, Builders. Launched Oct. 21, 1797.] Again, the largest naval gun in the year 1800 was one firing but a 42-pound shot, while in the United States navy we have now the 13-inch rifle of 60 tons, with a projectile of 1100 pounds, and Great Britain has afloat 1800-pounder breech-loaders which weigh 111 tons. Before monster ordnance such as this, the strength of man, unaided, is but crude and futile. He must call to his help—as he has done—steam as the source of power for the electric, hydraulic, or pneumatic engines, which load, elevate, and train the gun. In summing up the service of steam, directly or indirectly, to the ship-of-war, it will be seen that the speed of the battleship has been increased by fully 50 per cent., and that of the cruiser has been doubled; that the displacement of the battleship is now three and one half times that of her sailing predecessor; and that, since the century’s birth, the gun has grown to such extent that the projectile for the Oregon’s main battery weighs 26 times that of the heaviest shot in the year 1800. This, however, is not all. Steam acts primarily, as well, to raise the anchor, to steer the ship, and to effect her lighting, heating, drainage, and ventilation. To the genius of James Watt there must be ascribed the possibility for the growth and change which have produced the modern man-of-war. Closely allied with mechanism in this evolution, has been the transformation of the structural material of the hull, which has passed from the hands of the shipwright in wood to the engineer who works with steel. The reasons for this are not far to seek. They lie, firstly, in the greater strength of the metal construction to withstand the vibration of swift and heavy machinery, and the strains arising from the unequal distribution of massive weights in a hull which pitches or rolls with the waves. With wooden ships, the present proportions would have been unattainable. Again, there is a marked saving in the weight of the hull proper of the steel vessel, which is not only stronger but lighter. This weight in the days of timber averaged fully one half of the displacement; while in the Oregon, whose tonnage, at normal draught, is 10,288, the hull percentage is 44.06, leaving a gain over the wooden vessel of 611 tons to be applied to armor, armament, or equipment. Finally, the durability of the metal vessel, with adequate care, greatly exceeds that of the wooden war steamer, whose average life was but 13 years.