Nasmyth said nothing for almost a minute, and both recognized that the
silence was significant. Then he rose abruptly.

"In one shape or other the trouble you suggested is one we will have
to face," he commented. "That's why I'm going to fire a big charge in
the blasting heading to-night. You can bring the giant-powder along,
Tom."

Mattawa appeared to be amazed, and Gordon stared at his comrade
curiously.

"If you fire that charge now, you'll naturally make an end of the
heading, and I understood your notion was to drive right under the
fall and blow the whole ledge out at one time," objected Gordon.
"Guess if you just rip the top of the rock off, as far as we have
gone, it will take us quite a while to make another tunnel, and money,
as I needn't remind you, is running out."

"Exactly!" agreed Nasmyth. "That extra work will have to be faced, but
if I can get a big charge in to-night I can cut down the ridge a foot
or two. Two feet less water will count for something in the valley,
and I'm going to make sure of it. It seems certain that somebody will
try to stop us by-and-by."

Gordon noticed the hard glint in Nasmyth's eyes, and knew that now
when he was being pushed back to the wall he meant to fight, and would
not shrink from a sacrifice. They had driven that uncompleted heading
at a heavy cost, cutting at first an open gallery in the face of the
rock, drenched with the spray of the fall. Then they had crawled into
the dripping tunnel hewn out by sheer force of muscle, for it was
seldom that powder could be used, and they had only a worn-out
machine, and had toiled crouching with scarcely room to bring a hammer
down on wedge or to hold the drill, while from odd fissures the icy
river poured in on them. Now, it seemed, all that severe effort was to
be practically thrown away, but he recognized that his comrade was
right. It was wiser to make sure of two feet than to wait until
somebody set the law in motion and stopped the work.

"Yes," he assented simply; "I guess it has to be done."

Mattawa entered with the magazine, and Nasmyth laid out several sticks
of giant-powder near the stove. There was a certain risk in this, but
giant-powder freezes, and when that happens one must thaw it out. It
is a singularly erratic compound of nitro-glycerine, which requires to
be fired by a powerful detonator, and, if merely ignited, burns
harmlessly. One can warm it at a stove, or even flatten it with a
hammer, without s