MECHANICS A.ND USEFUL ARTS. 63 



telescopic in shape, and covered on the top with a grating to keep out 

 shells. The vessel is propelled by a pair of horizontal engines, each 

 having a cylinder forty inches in diameter, with a stroke of twenty- 

 two inches. Ventilating blowers are used, and the cold air is drawn 

 through the top of the turret. 



The fifteen-inch guns carried in the turret of the "VVeehawken, and 

 upon other of her companion vessels, weigh nineteen tons each, and 

 are the largest pieces of ordnance ever tried on shipboard. They are 

 easily worked, however, through the aid of newly devised machinery, 

 by three men ; and are fired through a muzzle box from within and 

 through the port-hole, and not, as usual, from the exterior, the port- 

 hole being only seventeen inches in diameter, while the face of the 

 muzzle of the gun is twenty-nine inches. 



Of other iron-clad vessels, one called the Keokuk, designed and 

 built for the U. S. Government by Mr. C. W. Whitney, of New York 

 City, differs essentially in its construction from any of the above re- 

 ferred to constructions. She is one hundred and fifty-nine feet long, 

 thirty-six feet three inches beam, and has thirteen feet six inches 

 depth of hold. There are two fixed turrets and a short smoke-pipe 

 visible above deck ; these alone break the smooth surface which every- 

 where slopes to the water's edge. The side armor extends four feet 

 below the fighting draft, which will be about eight feet six inches, and 

 for a portion of the length, amidships, presents an angle of thirty- 

 seven degrees to the horizon. This inclined armor runs up to the 

 main deck on each side, which is but little wider than the turrets. 

 The bow and stern of the Keokuk round away to the water, and pre- 

 sent the same appearance to the eye that a wasp's body would im- 

 mersed. The deck beams are a continuation of the ship's ribs, which 

 are of iron, four inches deep by one inch thick, placed eighteen inches 

 apart. Over these ribs a half-inch plate is laid, and that relaid again 

 with a five-inch wooden deck ; this latter is caulked water-tight, and 

 then armed with two half-inch iron plates, somewhat similar to the 

 Ericsson Monitors. The casemated portion of the vessel, five and 

 three-fourths inches thick, is laid with iron four inches deep by one 

 inch thick, placed one inch apart, the interstices being filled in with 

 yellow pine. The remaining one and three-fourths inches are made 

 up by the outside sheets. This armor is fastened on with countersunk 

 bolts one and one-eighth inches in diameter and twelve inches apart, 

 secured inside with strong, six-sided nuts. The deck has only seven- 

 eiorhth bolts through it. 



^H ^3 



The turrets, two in number, are stationary, and mount one eleven- 

 inch gun each. They are fourteen feet in diameter at the top, and 

 twenty feet at the base, extending seven feet above the deck, and 

 twenty inches below it ; and upon a platform constructed at that line 

 the guns are mounted. The turrets proper consist of wrought-iron 

 skeletons, made of flat iron, five inches deep by one inch thick, placed 

 edgewise, fifteen inches apart, and secured to a half-inch sheet by four 

 wrought-iron clamps four inches deep by one inch thick. The fifteen- 

 inch spaces remaining inside are filled up with wood, and afterward 

 covered with a thin sheet-iron lining, to make a smooth finish ; out- 

 side of the turret-skin, half-inch plate, the protection is the same as 

 that of the casemates. Each turret has its own shot, shell, and pow- 



