Frank blushed with pleasure. But one would never have known that his cheeks reddened, for he was black with grease and oil, having been engaged in going over the mechanism before he made the shot. The smoke was gradually blackening every one.
No sooner had the gun recoiled and moved back into place again, than compressed air rushed automatically into the breech and barrel, to drive out any slow-burning pieces of powder that might possibly ignite the next charge when it was inserted.
“Once more!” called the officer in charge, as up came the supply of powder and the projectile. Ned and his mates shoved them into the gun, and again the breech was closed with a clang.
“Listen for the range,” directed the officer. “They may try to fool us.” For in order to get as nearly as possible to actual war conditions, the target-towers were often instructed to run a zigzag course, sometimes close to, and again far away from the firing ship.
Once more came the signal into the turret from the range-finder.
“Whew!” commented the officer. “They’re running in on us.”
As has been said, in order to reach a far distant point, a gun must be elevated more than to hit a mark close by.
“Down she goes!” Frank exclaimed, as the mechanism depressed the muzzle.
“Can you sight the target?” asked the officer.
Again came that belch of smoke and acrid smell, the recoil of the gun, the trembling turret and the rush of compressed air as it blew out the burning particles of powder.
Powder that is used in big guns is not like the old-fashioned black powder. It is highly explosive, but some of the “grains” are in sheets, perforated like a piece of Swiss cheese, and as large as your palm. Some is in long sticks, like large macaroni. Other is in brown hexagons, two inches across. You can safely touch a match to some of this powder and let it burn as you hold it. It is when it is confined, as in a gun, and the gases from it can not escape after its sudden detonation, that it exerts its explosive force.
So the target practice went on, the young blue-jackets taking turns at sighting and firing the gun. But no one bettered Frank’s record of shots though Ned came close to it. It was hot work in the turret. The boys were stripped to their waists, and even then they were wet with perspiration and blackened with smoke and oil.