CHAPTER XIV--A BRAVE ACT

Target practice with our big guns aboard a battleship is rather an important occasion, as it is not often done. It is too expensive to fire away hundreds of pounds of powder and projectiles, the cost of which runs into the thousands. But it must be done occasionally.

When it is done, in order to get as nearly as possible to actual war conditions, it is customary to have the unexpected happen. That is to say, the target, which is a big square of canvas on a float, is towed by some other ship, and where or when it is to appear is not known to the men who work the guns. This is to make them quick and resourceful.

"Watch out now, men," advised the officer. "Arden, keep your wits about you. Remember there is quite a swell on to-day, and allow accordingly when you point the gun."

It might be stated here that the big guns are moved and controlled by machinery, but the machinery is under the fingers of the pointer and his assistants. By a simple movement of a lever the gun can be shifted up or down or from side to side. And probably all know that elevation is one of the most important matters in firing.

If a gun is taken, or for that matter a bean-shooter, and some projectile is fired or blown through the air, it will be noticed that it goes in a straight line for only a short distance. Then it begins to curve down and fall. This is due to loss of energy, and to the attraction of gravitation.

Now if the gun be held, say, exactly parallel to the earth's surface, it will be noted that the projectile will go a certain distance. Lower the gun, and it will not go so far. Raise it and the bullet (or bean, if the trial is made with a bean-shooter) will go much farther. And it is this angle of fire that is most important.

By computation it is possible to know at just what angle or inclination to point the gun in order to send its projectile to a certain point at a known distance away. And in order to find this distance it is necessary to use what are called range-finders.

These are something like telescopes, but the science known as triangulation is brought into use, also. So a range-finder on a battleship can in a short time signal to the gun-pointer just how far away a certain hostile ship or a target may be. When the gun-pointer knows the distance, he knows just how much to elevate or depress his gun in order to make the projectile come somewhere near the object at which he is aiming.

"All ready now. I think we'll get the range soon," said the officer in charge of the turret where Ned and Frank were stationed.

Every one was on the alert. The lads stood at attention. Into the breech of the big gun had been put the steel projectile, and back of that the powder, hundreds of pounds of it. Frank stood ready to press the trigger, which would detonate the primer and explode the charge. In front of him was the telescope sight, and at his fingers' ends were the controls that would move the gun whichever way he wished. Ned stood at the ammunition hoist.

A shrill whistle sounded in the turret. The officer in charge listened.

"The range is thirteen thousand yards," he said. An observer in a crow's-nest on one of the masts had sent in this information. The target was just coming into view, and through the range-finder the distance was quickly computed.

"Aye, aye, sir!" answered Frank in response to the officer. Then he bent down to peer through the telescope sight.

"Can you see it?" asked the officer.

"Not yet----there it is!" cried Frank, suddenly.

"Fire when you sight it properly."

There was a moment's hesitation. Then Frank's finger pressed on the lever that would send the great projectile on its way.

Such a crash followed that every one was deafened for a moment, in spite of the fact that every man in the turret stood on his toes to lessen the shock, and had his ears stuffed with cotton. The great gun recoiled, the back action being taken up by shock-absorbers, however. A sharp, acrid smell filled the turret. Smoke drifted in. Men staggered back and opened their mouths for air. It seemed as if ten thousand thunder claps had been made into one.

Then came a silence.

"Do you think you hit it?" asked Ned, and his voice sounded so strange, after the great crash, that nearly every one laughed.

"Silence!" called the officer in charge.

Again came a whistle through the speaking tube.

"Yes!" answered the listening officer. "A hit? Good! You made a hit the first try!" he shouted to Frank. "Try again."

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.

"Eight thousand yards!"

"Whew!" commented the officer. "They're running in on us."

"Have to lower the gun," commented Ned.

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.

"Sight she is!"

"Then fire!"

"Fire!" echoed Frank.

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.

Finally there flashed into view on the turret signal device the words "cease firing." The practice was over. And then, just how it happened no one could tell, there was discovered on the iron floor of the turret a burning mass of powder that was slowly flaming. And worse than that, this burning powder was near a large charge that had been hoisted up but not used.

"Look!" cried Ned, frantically.

"Run out!" shouted Frank, aware of the danger of an explosion.

"Clear the turret!" yelled the officer. "Out, every one of you!"

The explosion was imminent. The officer stood at the entrance as the lads rushed out. Frank was the last, being preceded by Hank Dell. As the latter hurried he slipped and fell, striking his head on a steel projection. With a moan he rolled over unconscious.

The next instant, though the explosion might occur any moment, Frank stooped over, and catching up in his strong arms the body of the unconscious bully, he bore him from the turret, though, had he wished, Frank might have leaped across the prone form to safety.

"Quick!" cried the officer, as he leaped after Frank to help him. But there was no need. Frank had carried out his enemy.

The next instant there was a big flash of fire, and a dull report that threw Frank with his burden down to the deck.