then again, the source may not be
some mountain stream running off under the lava, as we have been
supposing. It is quite possible that it is a spring which comes up
through the sandstone, and not being able to get up to daylight because
of the lava-cap, goes worming its way through innumerable crevices to
the underground reservoir we suppose to exist somewhere beneath the
surface of the Second Mesa."

"That is certainly a possibility," replied my father. "Nevertheless, it
is my opinion that it will be well worth while making an examination of
the creeks on Mount Lincoln. The streams to search would be those
running on a sandstone bed and coming against the upper face of the
lava-flow. It is worth the attempt, at least, and when the snow clears
off you boys shall employ any off-days you may have in that way."

"It would be well, wouldn't it, to tell Tom Connor about it?" suggested
Joe. "He would keep his eyes open for us. I suppose prospectors as a
rule don't take much note of such things, but Tom would do so, I'm sure,
if we asked him."

"Yes," replied my father. "That is a good idea; and if either of you
should come across your friend, the hermit, again, be sure to ask him.
He knows Mount Lincoln as nobody else does, and if he had ever noticed
anything of the sort he would tell us. Don't forget that. And now to
bed."

CHAPTER X

HOW TOM CONNOR WENT BORING FOR OIL

One thing was plain at any rate: we could do nothing towards finding the
source of the underground stream until the snow cleared off the
mountain, and that was likely to be later than usual this year, for the
fall had been exceedingly heavy in the higher parts. We could see from
the ranch that many of the familiar hollows were obliterated--leveled
off by the great masses of snow which had drifted into them and filled
them up.

We therefore went about our work of hauling stone, and so continued
while the cold weather lasted, interrupted only once by a heavy storm
about the end of January, which, while it added another two feet to the
thick blanket of snow already covering the mountains, quickly melted off
down in the snug hollow where the ranch lay, so that our work was not
delayed more than two or three days.

One advantage to us of this storm was that it enabled us to learn
something--not much, certainly, but still something--regarding the
source of the stream in the fissure. It did not show us where that
source was, but it proved to us