Caleb Walton laughed outright. "Don't try to learn it all before you go to bed, Walter," he said. "Of course, you know more than some landlubbers who think that on warships of to-day they handle the guns as they used to, when one man took the powder and ball from the powder-monkeys, another rammed them home in the gun, and the gunner sighted his piece and pulled the string. Those days are gone, and a head gunner like myself has very little to do, even if the position is a responsible one. Come, I'll get permission to go below, and show you just how a big gun is served from start to finish. Folks talk about 'the man behind the gun' when they really mean from eight to twelve men." The two hurried off, and presently descended an iron staircase which seemed to lead into the very bowels of the ship. At last they came to a steel trap-door, barred and locked. "Below this door is one of the magazines," explained Caleb. "It contains the ammunition for the eight-inch guns in the turret above. The keys to the magazine are in the captain's cabin, and can only be had on special order and by certain persons. The magazines are kept locked continually, excepting when in use or when being inspected. All of them are connected with huge water tanks, so at the first sign of a fire they can be flooded, thus lessening the danger of an explosion." "Yes, I remember the Spaniards tried to prove that the _Maine_ blew up from one of her magazines." "Such a thing couldn't happen in the American navy, because the discipline is too strict. Now, when a gun is being served, several men in the magazine get out the shells for the shellmen, who load them on the ammunition hoist over there, which is nothing more than a warship dumbwaiter. The hoist takes the shells up to the guns, in this case in the forward turret. Other hoists supply the rear turret and the secondary battery and other guns, including the rapid-firing weapons in the military tops." "You mean those platforms around the upper ends of the two masts?" "Exactly. The tops are the places for the sharpshooters and the range-finders." "The range-finders?" "Exactly. You see, it is a difficult matter to get an exact range on an enemy several miles off, and we have to try to get the range in various ways. One of the simplest ways is to station two range-finders in the tops, as far away from each other as possible. Each man gets a bead on the enemy with his glasses, and then proceeds to get the angle between the bead and an imaginary line drawn between his station and that taken by the other fellow. The three points--that is, the two range-finders and the enemy--form a triangle, and having one line and the two angles to work on, the working out of the problem gives the distance the gunners are hunting for." "That makes pointing a gun nothing but a mathematical problem doesn't it?"