"You know and I know that the water didn't push this out.
How about that flash and bang we heard last night?"

"I can't see how the water could have done it," said Bill, who evidently
had more talent for construction than for determining destruction.

"There's something behind this that I don't like and I'm going to find
out about it," said Gus, his usually quiet demeanor entirely gone. "You
ought to be able," he continued, "to put two and four together. How
about that warning Grace gave you? And how did she know anything out of
which to give it? And why wouldn't she give any names?"

"Well, I have wondered; I thought I saw why," Bill said.

"Of course you see why, old scout. And if you'll leave it to me, you'll
know why and all the how and the what of it, too." Gus was never
boastful; now he was merely determined.

The boys opened the flood gate and after the water no longer flowed
through the break, they began a closer examination that surprised them.
Mr. Hooper, Thad, Grace and Skeets descended the hill.

Bill, after greetings, merely pointed to the break. Mr. Hooper started
to say something about the structure's being too weak; Thad laughed, and
Grace, looking daggers at him, turned away and pulled Skeets with her.
Gus, gazing at Thad, addressed Mr. Hooper.

"Yes, too weak to stand the force of an explosion. It wasn't the water
pressure. Mr. Hooper; you'll notice that the stones there are forced in
against the water; not out with it. And the cracks--they're further
evidence. We heard the explosion about eleven o'clock; saw the light of
the flash, too."

"Shucks! You reckon that's so? Got any notion who it was that done it?"

"Yes, sir; got a big notion who it was; but we won't say till we get it
on him for sure. And then's it's going to be a sorry day for him."

Gus was still gazing straight at Thad and that youth, first attempting
to ignore this scrutiny and then trying to match it, at last grew
restless and turned away. Mr. Hooper also had his eyes on Thad; the old
gentleman looked much troubled. He raised his voice loud enough for Thad
to hear as he walked off:

"We'll git a watchman an' put him on the job,--that's what we'll do!
They ain't goin' to be any more o' this sort o' thing."

And Bill chimed in: "Good idea. There's George, Mr. Hooper; we're nearly
through with him and we've been wondering what to put him at, for we'd
be sorry to lose him."

So it was arranged then and there, much to the s