They examined what was left of it with great care.

Finishing their investigation, the two men looked at each other with eyes full of meaning.
"Well, what do you think of it ?" questioned Hippy.
"I think, Hip, that it was something more than structural weakness that caused this dam to go out," answered Tom.
"What do you think did it--I mean how was it done ?" wondered Lieutenant Wingate.
"Dynamite!" The word came out with explosive force.

"The pirates don't like our presence here, so thought they would put us out of business.
They didn't know us, did they, Hippy ?" "No.

I wonder what they will think now--or do ?" "Nothing in the way of damaging our property, for we shall have our works watched after this.

They might blow the upper dam, of course, but there are no logs being held there and the water would simply flow over our construction without doing damage.