the text-books and took every opportunity offered them to gain knowledge in that branch of the service.

"Hi, fellows!" called Torry, having stopped the car. "Going to stand there gassing all day?"

The three figures in seaman's dress broke away from their admiring friends and approached the automobile. Frenchy Donahue was a little fellow with pink cheeks, bright eyes, and an Irish smile. Ikey Rosenmeyer was a shrewd looking lad who always had a fund of natural fun on tap. The older man, Hans Hertig, was round-faced and solemn looking, and seldom had much to say. He had had an adventurous experience both as a fisherman and naval seaman, and really attracted more attention in his home town than did the four boy chums.

"Get in, fellows," urged Torry. "We want to be sure to catch those chaps at Elmvale during the noon hour. They go home from the munition works for dinner, and we must talk with them then."

Frenchy and Ikey and Seven Knott climbed into the tonneau and the car whizzed away, leaving the crowd of boys and girls, and a few adults, staring after them.

"By St. Patrick's piper that played the last snake out of Ireland!" sighed Frenchy, ecstatically, "we never was of such importance since we was christened—hey, fellows?"

"Oi, oi!" murmured Ikey, wagging his head, "my papa don't even suggest I should take out the orders to the customers no more. He does it himself, or he hires a feller to do it for him.

"Mind, now! Last night he closed the shop an hour early so's to sit down with my mama and me and Aunt Eitel in the back room, after the kids was all in bed, and made me tell about all we'd done and seen. I tell you it's great!"

"And before we began our hitch," Al Torrance chuckled, as he expertly rounded a corner, "we were scarcely worth speaking to in Seacove. Now folks want to stop us on the street and tell us how much they think of us."

"Gee!" exploded Frenchy, "I could eat candy and ice cream all day long if I'd let the kids spend money on me."

"We're sure some pumpkins," drawled Whistler Morgan, dryly, sitting around in the front seat so he could talk with those in the rear. "I say, Hans!"

"Yep?" was Seven Knott's reply.

"Do you really think we can get some of those fellows at Elmvale to go to the recruiting office and enlist?"

"Yep. You fellows can tell 'em. You can talk better'n I can."

Seven Knott knew his shipboard duties thoroughly, and never was reprimanded for neglect of them. But since the four chums had known him well, the petty officer had been no conversationalist, that was sure.

"If this war was going to be won by talk, like some fellows in Congress seem to think," Al Torrance once said, "Seven Knott wouldn't have a chance. But it is roughnecks just like him that man the boats and shoot the guns that are going to show Kaiser Bill where he gets off—believe me!"

Elmvale was a factory town not more than six miles above Seacove. It was on the river, at the mouth of which was situated the little port in which were the homes of Whistler Morgan and his friends.

The biggest dam in the State, the Elmvale Dam, held back the waters of the river above the village; and below the dam were several big mills and factories that got their power from the use of the water.

On both sides of the stream, and around the cotton mills, the thread mills, and the munition factories, were built many little homes of the factory and mill hands. It had been pointed out by the local papers that these homes were in double peril at this time.

Guards were on watch night and day that ill-affected persons should not come into the district and blow up the munition factories. But there was a second and greater danger to the people of Elmvale.

If anything should happen to the dam, if it should burst, the enormous quantity of water held in leash by the structure would pour over the village and cover half the houses to their chimney tops.

Two bridges crossed the river at Elmvale; one at the village proper and the other just below the dam itself and about half a mile from the first mill, Barron & Brothers' Thread Factory.

"Let's take the upper road," proposed Frenchy, as the car came within sight of the chimneys of the Elmvale mills. "We've plenty of time before the noon whistle blows. I haven't been up by the dam since before we all joined the Navy."

"Just as you fellows say," Al responded, and turned into a side road that soon brought them above the mills on the ridge overlooking the valley.

"I say, fellows," Whistler stopped whistling long enough to observe, "there's a slue of water behind that dam. S'pose she should let go all of a sudden?"

"I'd rather be up here than down there," Al said.

"Oi, oi!" croaked Ikey, "you said something."

"I wonder if they guard that dam as they say they do the munition factories," Frenchy put in.

Al turned the machine into the road that descended into the valley by a sharp incline. In sight of the bridge which crossed the river Whistler suddenly put his hand upon his chum's arm.

"Hold on, Torry," he said earnestly. "I bet that's one of the guards now. See that fellow in the bushes over there?"

"I see the man you mean!" Frenchy exclaimed, leaning over the back of the front seat of the automobile. "But he isn't in khaki. And he hasn't got a gun."

All the Navy boys in the automobile, even Seven Knott, saw the man to whom Whistler Morgan had first drawn attention. The man had his back to the road. He was standing upright with a pair of field glasses to his eyes. His interest seemed fixed on a point along the face of the dam just where a thin slice of water ran over the flashboard into the rocky bed of the river.

CHAPTER II

THE STRANGER

For the life of him Phil Morgan could not have told why he was so keenly interested in that stranger. He could not see the man's face; he did not presume it was anybody he had ever seen before; nor had he any reason to be suspicious of the man.

Nevertheless he felt a little thrill as he first caught sight of the stranger, and this feeling spurred his exclamation to Torry, which lead the others' attention to him.

After they had all seen the man, Phil added: "Pull her down. Let's see what he is up to."

Torrance stopped the automobile. His chum was their acknowledged leader in most things, and all the other Navy boys were used to obeying Phil Morgan's mandates without much question. As told in the former books of this series, Morgan was an observant and level-headed youth, and his friends might have followed a much more dangerous leader in both work and play.

The four boys, at that time all under eighteen years of age, had begun their first enlistment in the Navy several months before the United States got into the war. They spent some months in the training camp at Saugarack, on the New England coast.

The Government commissioned new craft of all kinds as rapidly as they could be obtained, and was obliged to man some of them partly with youths who had not yet finished their preliminary training ashore.

Phil Morgan and his friends had made rapid progress in their studies and the drills, and they were lucky enough to be assigned to the same ship. This was the destroyer Colodia, one of the newest of her class, a fast ship of a thousand tons' burden. She made two cruises, both crammed full of excitement and adventure; and the story of these cruises is related in the first volume of the series, entitled "Navy Boys After the Submarines; Or, Protecting