The bridge was a low one and only twenty yards up the stream from the falls; but though they strained their eyes to the uttermost they couldn't see as far as the dam.
"I'll turn one of the headlights," said Archey, "and we'll drive over slow." The lamp, turned at an angle, swept over the edge of the dam like a searchlight.

Half way over the bridge the car stopped.

They had found what they were looking for.
"Why doesn't it go over ?" shouted Archey, jumping out.
"Anchored to a tree up the bend, I guess," Paul shouted back.

"They must have played her down the stream after dark." Nearly over the dam was a boat painted black and covered with tarpaulin.
"The explosive is probably hanging from a chain underneath," thought Paul.

"The current would hold it tight against the mason-work." "We ought to have brought some help," shouted Archey, suddenly realizing.
"If that dam breaks, it will sweep away the factory and part of the town....