s chill pierced him like knives, and
compressed his head as with a band of iron.

Looking up through the crystal sheet, he could see an apparently endless
line of bubbles rising from where he was to the surface, and, after a
while, he began to follow them. With a breathless gasp he again reached
the blessed air, and, dashing the water from his eyes, began to consider
his situation. He was dazed and bewildered at finding himself still
alive and apparently none the worse for his tremendous slide. Although
he was in bright sunlight, the mountain-side down which he had come was
hidden beneath dense folds of cloud, out of which he seemed to have
dropped.

Gently paddling with his hands, just enough to keep himself afloat, Glen
looked anxiously about for some beach or other place at which he might
effect a landing, but could discover none. The upper edge of the
snow-field, that bounded the lake on one side, projected far over the
water, so that, while he might swim under it, there was no possibility
of getting on it. On all other sides sheer walls of rock rose from the
water, without a trace of beach, or even of boulders, at their base.

In all this solid wall there was but one break. Not far from where Glen
swam, and just beyond the snow-field, a narrow cleft appeared; and from
it came an indistinct roar of waters. Glen felt himself growing numbed
and powerless. He must either give up at once, and tamely allow himself
to sink where he was, or he must swim to that cleft, and take his
chances of getting out through it. He fully expected to find a waterfall
just beyond the gloomy portal, and he clearly realized what his fate
would be if it were there. But whatever he did must be done quickly. He
knew that, and began to swim towards the cleft.

As he approached it, he felt himself impelled onward by a gentle current
that grew stronger with each moment. Now he could not go back if he
would. He passed between two lofty walls of rock, and, instead of
dashing over a waterfall, was borne along by a swift, smooth torrent
that looked black as ink in the gloom of its mysterious channel.

Ere the swimmer had traversed more than fifty yards of this dim
waterway, the channel turned sharply to the left, and the character of
the lower portion of its wall, on that side, changed from a precipice to
a slope. In another moment Glen's feet touched bottom, and he was slowly
dragging his numbed and exhausted body ashore.

Although the sun was