of the fateful words spoken by Captain Wiltsey. But it
needed only a look at his face to tell that he was laboring under
great excitement.

"The Gatun Dam to be destroyed," repeated Joe. "Then we'd better
get--"

"Do you mean by an earthquake?" asked Blake, breaking in on his
chum's words.

"No, I don't take any stock in their earthquake theories," the
captain answered. "That's all bosh! It's dynamite."

"Dynamite!" cried Joe and Blake in a breath.

"Yes, there are rumors, so persistent that they cannot be denied,
to the effect that the dam is to be blown up some night."

"Blown up!" cried Blake and Joe again.

"That's the rumor," continued Captain Wiltsey. "I don't wonder you
are astonished. I was myself when I heard it. But I've come to get
you boys to help us out."

"How can we help?" asked Blake. "Not that we won't do all we can,"
he added hastily, "but I should think you'd need Secret Service
men, detectives, and all that sort of help."

"We'll have enough of that help," went on the tug boat commander,
who was also an employee of the commission that built the Canal.
"But we need the peculiar help you boys can give us with your
cameras."

"You mean to take moving pictures of the blowing up of the dam?"
asked Joe.

"Well, there won't be any blowing up, if we can help it," spoke
the captain, grimly. "But we want to photograph the attempt if it
goes that far. Have you any flashlight powder?"

"Yes," Blake answered. "Or, if not, we can make some with
materials we can easily get. But you can't make more than a
picture or two by flashlight."

"Couldn't you if you had a very big flashlight that would last for
several minutes?"

"Yes, I suppose so."

"Well, then, figure on that."

"But I don't understand it all," objected Blake, and Joe, too,
looked his wonder. Both were seeking a reason why the captain had
said he was glad Mr. Alcando had gone out to get the camera he had
forgotten.

"I'll explain," said Mr. Wiltsey. "You have no doubt heard, as we
all have down here, the stories of fear of an earthquake shock. As
I said, I think they're all bosh. But of late there have been
persistent rumors that a more serious menace is at hand. And that
is dynamite.

"In fact the rumors have gotten down to a definite date, and it is
said to-night is the time picked out for the destruction of the
dam. The water of the Chagres River is exceptionally high, owing
to the rains, and if a breach were blown in the da