described for the British ship Téméraire. This change is only a partial remedy; the disadvantage of the open-top tower slightly above the level of the water still remains. 2d. The second objection is that the side armor-plates do not extend deeper below the water-line than in ordinary vessels, and as the Admiral Popoff is 121 feet in diameter, there is this large target at all times presented for under-water attack by locomotive-torpedoes, instead of the bow or stern alone, as would often happen in the attacks on other vessels. The extra defense against torpedoes gained from the cellular construction by means of the circular system would avail nothing. 3d. The third objection consists in the complication of the motive machinery. There are six screw-propellers, operated by three sets of engines. Two of the propellers have diameters greater than the draught of the vessel, the periphery of the blades extending below the keel. These two screws are three-bladed, and are not worked in shallow water. I had considerable experience, during our civil war, on the Mississippi River, in building and operating the machinery of the four large wide flat-bottomed gun-vessels of the Milwaukee class, provided with four screw-propellers. I, therefore, think I know what the complication of the machinery for six must be. Moreover, I do not see that the six screw-propellers are protected from attacks of any kind. 4th. The fourth and most serious objection to the circular form of vessels consists in the extraordinary steam-power necessary to drive a ves sel, say, of 121 feet diameter, through the water at a speed equal to that of the ordinary vessel of the same carrying capacity. The weight and space occupied by the machinery would be so great as to leave but little room for all the other requirements. Mr. Reed says that the Novgorod made a speed on the measured mile of 8 knots; that she has steamed a considerable distance at 71⁄2 knots; and when he made a trip in her the speed averaged 63 knots. This last is probably the real speed when steaming in ordinary weather for a period of twenty-four or more hours. If the weights of the steam-machinery had been given, and other necessary data, the weights, &c., for higher speeds could be readily estimated. The first objection raised to the circular vessel, viz, the open-top tower, could be remedied in future constructions by substituting the Ericsson revolving turret, and the second objection could be removed by extending the vertical side-armor down to the keel. This would entirely protect the vessel from the attacks of moving torpedoes. The third objection may be obviated, but the fourth is insurmountae. Therefore for sea-going vessels, although the form may be changed by adding ends, as shown at figure 8, the principle of construction will Hot be likely to meet with favor from naval architects, much less from naval officers. The list of Russian armed ships with the principal dimensions is given herewith. |