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 geyser, five years old.”  In fact, in 1891, a sudden outburst of volcanic fury made an opening here, through which, at intervals of thirty minutes, day and night, hot water now leaps forth in wild confusion.

“This, then, is a geyser!” I exclaimed.

“Bah!” said the guide, contemptuously, “if you had seen the real geysers in the Upper Basin, you would not look at this.”

[Illustration:  A BABY GEYSER.]

Meantime, for half an hour we had been hearing, more and more distinctly, a dull, persistent roar, like the escape of steam from a transatlantic liner.  At last we reached the cause.  It is a mass of steam which rushes from an opening in the ground, summer and winter, year by year, in one unbroken volume.  The rock around it is as black as jet; hence it is called the Black Growler.  Think of the awful power confined beneath the surface here, when this one angry voice can be distinctly heard four miles away.  Choke up that aperture, and what a terrible convulsion would ensue, as the accumulated steam burst its prison walls!  It is a sight which makes one long to lift the cover from this monstrous caldron, learn the cause of its stupendous heat, and trace the complicated and mysterious aqueducts through which the steam and water make their way.

[Illustration:  THE BLACK GROWLER.]

Returning from the Black Growler, we halted at a lunch-station, the manager of which is Larry.  All visitors to the Park remember Larry.  He has a different welcome for each guest:  “Good-day, Professor.  Come in, my Lord.  The top of the morning to you, Doctor.”  These phrases flow as lightly from his tongue as water from a geyser.  His station is a mere tent; but he will say, with most amusing seriousness:  “Gintlemen, walk one flight up and turn to the right, Ladies, come this way and take the elevator.  Now thin, luncheon is ready.  Each guest take one seat, and as much food as he can get.”

“Where did you come from, Larry?” I asked.

[Illustration:  LARRY.]