was broad-shouldered, walked
with a brisk military step, and was heavily bewhiskered.

Whistler stopped talking to a possible candidate for the blue uniform of
the Navy, and looked after this stranger.

"Who is he?" he asked.

"That's Blake. Works in our laboratory. Nice fellow," was the reply.

"Oh! I didn't know but he was one of the men guarding the dam," Whistler
murmured.

"Shucks! there aren't any guards up there. There are soldiers here at
the factories, though."

"Is that so?" questioned Whistler. "Where's he been, do you suppose?"

"Who? Blake?"

"That man," said young Morgan grimly.

"Oh, he's a bug on natural history, or the like. Always tapping rocks
with a hammer, or hunting specimens, or botanizing. Great chap. Hasn't
been here in Elmvale long. But everybody likes him."

Phil made no further comment aloud, but to himself he said:

"He wasn't botanizing through that field-glass; or knocking specimens
off of rocks. His interest was centered on the face of the dam. I wonder
why?"

For the military looking man, called Blake, was the individual he and
his friends had seen in the bushes as they drove along the Upper Road,
and who had seemed desirous of being unobserved by the passers-by.

CHAPTER III

THE WATER WHEEL

Phil Morgan was no more suspicious by nature than his chums. Merely a
thought had come into his mind that had not come into theirs; and he
disliked to be annoyed by anything in the nature of an unsolved problem.
He always wanted to know why.

In this particular case he wished to know why the man called Blake had
tried to hide himself in the clump of bushes beside the Upper Road when
the automobile load of boys had come along and caught him examining the
face of the Elmvale Dam through a field-glass.

It was through a break in the trees that partly masked the dam the man
had been looking, and Whistler knew that the spot in which he was
interested must be directly beside the overflow of the dam--where the
water splashed down into the rocky river bed.

Whistler did not lose interest in the attempt to inspire some of the
factory workers to enlist in the Navy, and he worked just as hard as his
mates all through the noon hour. But the puzzle connected with the man
named Blake continued to peck at his mind like an insistent chick trying
to get out of its shell.

Hans Hertig's desire to get some of his old friends to enlist bore some
fruit. Three men promised to go down to