Page:Nurse and spy in the Union Army.djvu/80

70 be made to revolve at the rate of sixty revolutions a minute, and can be regulated to stop within half a degree of a given point. When the guns are drawn in to load, the port-hole is stopped by a huge iron pendulum, which falls to its place, and makes that part as secure as any, and can be quickly hoisted to one side. The armanent consists of two eleven-inch Dahlgren guns. Various improvements in the gun-carriage enable the gunner to secure almost perfect aim.

"The engine is not of great power, as the vessel was designed as a battery, and not for swift sailing. It being almost entirely under water, the ventilation is secured by blowers, drawing the air in forward, and discharging it aft. A separate engine moves the blowers and fans the fires. There is no chimney, so the draft must be entirely artificial. The smoke passes out of gratings in the deck. Many suppose the Monitor to be merely an iron-clad vessel, with a turret; but there are, in fact, between thirty and forty patentable inventions upon her, and the turret is by no means the most important one. Very properly, what these inventions are is not proclaimed to the public."