annexed sketches show the large guns fifteeninch caliber by sixty-two and one-half feet long, but the rigid mounting prevents drooping of the end of gun, and no doubt a satisfactory sixteeninch gun of, say, fifty calibers, or a still larger gun, would be available. The elevation of these large guns is effected by tilting the whole globular battery. This is done by moving weighted cars on arc-shaped tracks. The azimuths are regulated by four screw-propellers. An eighteen-inch armor belt twenty-nine feet wide extends all around the globular battery, perfectly protecting the main deck, the berth deck, and the hull for ten feet below water-line. The gundeck, upper deck, tower, and barbettes have twelve-inch armor. The sides of these decks are very sloping, and the tower and barbettes small and circular. No vessel afloat has anything like such protection. Only a globular battery could carry such a weight of armor.

It is not intended that the battery should be able to move rapidly from place to place; and small engines would be sufficient to work the screws or other mechanisms which rotate the battery, or move it slowly from place to place, and to operate ventilation, ice and electrical plants, etc. Thus, there is much saving in the weight and space required for machinery, coal, etc., so that heavier armor and more stores can be carried; and the Trident, equipped with a condensing plant, could remain abroad or at sea off our coast for many months without needing any supplies whatever. There is room on board for a large force of men, but a small force would be sufficient fully to equip her on a war basis, while in times of peace she could be maintained at a very small expense.

The Trident has advantages of superposed turrets without their weakness. There are no turret rollers to break when large guns are discharged. One such globular battery would blockade the entrance to the Mediterranean Sea, where the strait is only seven and three-quarter miles wide, could protect a mouth of a transcontinental canal, or could defend seaward or threaten almost any large seaport, and could safely resist a dozen of the largest battle-ships, which cost $7,500,000 apiece.1 For many