orward, but suddenly dashed against a solid mountain made of
glass. Through that, he said, he had been looking at the animal.
Unspeakably amazed, he finally walked around the mountain, and was
just taking aim again, when he discovered that the glass had acted
like a telescope, and that the bear was twenty-five miles away! Not
far from the volcanic cliff which gave the trapper inspiration for
his story, we reached one of the most famous basins of the Park. In
briefest terms, these basins are the spots in the arena where the
crust is thinnest. They are the trap-doors in a volcanic stage
through which the fiery actors in the tragedy of Nature, which is
here enacted, come upon the scene. Literally, they are the vents
through which the steam and boiling water can escape. In doing so,
however, the water, as at the Mammoth Springs, leaves a sediment of
pure white lime or silica. Hence, from a distance, these basins look
like desolate expanses of white sand. Beside them always flows a
river which carries off the boiling water to the outer world.

[Illustration: THE NORRIS BASIN.]

[Illustration: A PLACE OF DANGER.]

No illustration can do justice to what is called the Norris Basin,
but it is horrible enough to test the strongest nerves. Having full
confidence in our guide (the Park photographer) we ventured with him,
outside the usual track of tourists, and went where all the money of
the Rothschilds would not have tempted us to go alone. The crust
beneath our feet was hot, and often quivered as we walked. A single
misstep to the right or left would have been followed by appalling
consequences. Thus, a careless soldier, only a few days before, had
broken through, and was then lying in the hospital with both legs
badly scalded. Around us were a hundred vats of water, boiling
furiously; the air was heavy with the fumes of sulphur; and the whole
expanse was seamed with cracks and honeycombed with holes from which
a noxious vapor crept out to pollute the air. I thought of Dante's
walk through hell, and called to mind the burning lake, which he
describes, from which the wretched sufferers vainly sought to free
themselves.

[Illustration: A CAMPING-STATION.]

Leaving, at last, this roof of the infernal regions, just as we again
stood apparently on solid ground, a fierce explosion close beside
us caused us to start and run for twenty feet. Our guide laughed
heartily. "Come back," he said, "don't be afraid. It is only a baby
gey