midnight callers went
on. Joe and Blake worked in silence, making ready for their part
in it. All about the boys, though they could neither see nor hear
them, were Uncle Sam's men--soldiers, some of them--stationed near
where, so rumor said, the attempt was to be made to explode the
dynamite.

"We really ought to have another helper," said Blake,
thoughtfully. "There is one place we can't get in focus no matter
how we try, with the three machines we have. If we had another
automatic it would be all right, but we have only the one. Another
hand camera would do, but we'd have to get someone to work it. I
would suggest we get Mr. Alcando, but you don't seem to want him.
He could easily take charge of one."

"It is better to have no foreigners," replied the captain. "Not
that Mr. Alcando might not be all right, for he seems a nice chap.
But he is a Spaniard, or, rather a South American, and some of the
South Americans haven't any too much love for us; especially since
the Canal was built."

"Why?" asked Blake.

"Oh, for various reasons. Some of them have lost trade because it
shortens routes. But there, I must go and see if all the men are
in place." Captain Wiltsey left him, and once more the moving
picture boy resumed his vigil. All about him was silence and
darkness. As well as he could he looked to see that his camera was
pointing in the right direction, and that it set firmly on the
tripod, the legs of which were driven into the ground.

"I'll just step over and see how Joe is," thought Blake. He judged
it lacked half an hour yet of midnight.

He found Joe busy mending a broken wire that ran from the battery
to the flashlight powder chamber.

"Just discovered it," Joe whispered. "Lucky I did, too, or it
would have failed me just when I needed it."

"Is it fixed?" asked Blake, as his chum straightened up in the
darkness.

"Yes, it'll do for a while, though it's only twisted together.
Say, but isn't it dark?"

"It sure is," agreed Blake.

Together they stood there near the great dam. There came to their
ears the splashing of water over the spillway, for the lake was
high, and much was running to waste.

"Well, I guess I'll be getting back," said Blake in a low voice.
"No telling when things will happen now."

As he started to go away Joe remarked:

"Where are you wearing your watch? I can hear it over here."

"Watch! I haven't mine on," Blake answered. "You can't see it in
the dark, so I left it on