Chapter 74 of Roughing It:

We got back to the schooner in good time, and then sailed down to Kau, where we disembarked and took final leave of the vessel. Next day we bought horses and bent our way over the summer-clad mountain-terraces, toward the great volcano of Kilauea (Ke-low-way-ah). We made nearly a two days’ journey of it, but that was on account of laziness. Toward sunset on the second day, we reached an elevation of some four thousand feet above sea level, and as we picked our careful way through billowy wastes of lava long generations ago stricken dead and cold in the climax of its tossing fury, we began to come upon signs of the near presence of the volcano—signs in the nature of ragged fissures that discharged jets of sulphurous vapor into the air, hot from the molten ocean down in the bowels of the mountain.
Shortly the crater came into view. I have seen Vesuvius since, but it was a mere toy, a child’s volcano, a soup-kettle, compared to this. Mount Vesuvius is a shapely cone thirty-six hundred feet high; its crater an inverted cone only three hundred feet deep, and not more than a thousand feet in diameter, if as much as that; its fires meagre, modest, and docile.—But here was a vast, perpendicular, walled cellar, nine hundred feet deep in some places, thirteen hundred in others, level- floored, and ten miles in circumference! Here was a yawning pit upon whose floor the armies of Russia could camp, and have room to spare.
Perched upon the edge of the crater, at the opposite end from where we stood, was a small look-out house—say three miles away. It assisted us, by comparison, to comprehend and appreciate the great depth of the basin—it looked like a tiny martin-box clinging at the eaves of a cathedral. After some little time spent in resting and looking and ciphering, we hurried on to the hotel.
By the path it is half a mile from the Volcano House to the lookout- house. After a hearty supper we waited until it was thoroughly dark and then started to the crater. The first glance in that direction revealed a scene of wild beauty. There was a heavy fog over the crater and it was splendidly illuminated by the glare from the fires below. The illumination was two miles wide and a mile high, perhaps; and if you ever, on a dark night and at a distance beheld the light from thirty or forty blocks of distant buildings all on fire at once, reflected strongly against over-hanging clouds, you can form a fair idea of what this looked like.
A colossal column of cloud towered to a great height in the air immediately above the crater, and the outer swell of every one of its vast folds was dyed with a rich crimson luster, which was subdued to a pale rose tint in the depressions between. It glowed like a muffled torch and stretched upward to a dizzy height toward the zenith. I thought it just possible that its like had not been seen since the children of Israel wandered on their long march through the desert so many centuries ago over a path illuminated by the mysterious “pillar of fire.” And I was sure that I now had a vivid conception of what the majestic “pillar of fire” was like, which almost amounted to a revelation.
Arrived at the little thatched lookout house, we rested our elbows on the railing in front and looked abroad over the wide crater and down over the sheer precipice at the seething fires beneath us. The view was a startling improvement on my daylight experience. I turned to see the effect on the balance of the company and found the reddest-faced set of men I almost ever saw. In the strong light every countenance glowed like red-hot iron, every shoulder was suffused with crimson and shaded rearward into dingy, shapeless obscurity! The place below looked like the infernal regions and these men like half-cooled devils just come up on a furlough.

I turned my eyes upon the volcano again. The “cellar” was tolerably well lighted up. For a mile and a half in front of us and half a mile on either side, the floor of the abyss was magnificently illuminated; beyond these limits the mists hung down their gauzy curtains and cast a deceptive gloom over all that made the twinkling fires in the remote corners of the crater seem countless leagues removed—made them seem like the camp-fires of a great army far away. Here was room for the imagination to work! You could imagine those lights the width of a continent away—and that hidden under the intervening darkness were hills, and winding rivers, and weary wastes of plain and desert—and even then the tremendous vista stretched on, and on, and on!—to the fires and far beyond! You could not compass it—it was the idea of eternity made tangible—and the longest end of it made visible to the naked eye!
The greater part of the vast floor of the desert under us was as black as ink, and apparently smooth and level; but over a mile square of it was ringed and streaked and striped with a thousand branching streams of liquid and gorgeously brilliant fire! It looked like a colossal railroad map of the State of Massachusetts done in chain lightning on a midnight sky. Imagine it—imagine a coal-black sky shivered into a tangled net- work of angry fire!
Here and there were gleaming holes a hundred feet in diameter, broken in the dark crust, and in them the melted lava—the color a dazzling white just tinged with yellow—was boiling and surging furiously; and from these holes branched numberless bright torrents in many directions, like the spokes of a wheel, and kept a tolerably straight course for a while and then swept round in huge rainbow curves, or made a long succession of sharp worm-fence angles, which looked precisely like the fiercest jagged lightning. These streams met other streams, and they mingled with and crossed and recrossed each other in every conceivable direction, like skate tracks on a popular skating ground. Sometimes streams twenty or thirty feet wide flowed from the holes to some distance without dividing—and through the opera-glasses we could see that they ran down small, steep hills and were genuine cataracts of fire, white at their source, but soon cooling and turning to the richest red, grained with alternate lines of black and gold. Every now and then masses of the dark crust broke away and floated slowly down these streams like rafts down a river. Occasionally the molten lava flowing under the superincumbent crust broke through—split a dazzling streak, from five hundred to a thousand feet long, like a sudden flash of lightning, and then acre after acre of the cold lava parted into fragments, turned up edgewise like cakes of ice when a great river breaks up, plunged downward and were swallowed in the crimson cauldron. Then the wide expanse of the “thaw” maintained a ruddy glow for a while, but shortly cooled and became black and level again. During a “thaw,” every dismembered cake was marked by a glittering white border which was superbly shaded inward by aurora borealis rays, which were a flaming yellow where they joined the white border, and from thence toward their points tapered into glowing crimson, then into a rich, pale carmine, and finally into a faint blush that held its own a moment and then dimmed and turned black. Some of the streams preferred to mingle together in a tangle of fantastic circles, and then they looked something like the confusion of ropes one sees on a ship’s deck when she has just taken in sail and dropped anchor—provided one can imagine those ropes on fire.
Through the glasses, the little fountains scattered about looked very beautiful. They boiled, and coughed, and spluttered, and discharged sprays of stringy red fire—of about the consistency of mush, for instance—from ten to fifteen feet into the air, along with a shower of brilliant white sparks—a quaint and unnatural mingling of gouts of blood and snow-flakes!
We had circles and serpents and streaks of lightning all twined and wreathed and tied together, without a break throughout an area more than a mile square (that amount of ground was covered, though it was not strictly “square”), and it was with a feeling of placid exultation that we reflected that many years had elapsed since any visitor had seen such a splendid display—since any visitor had seen anything more than the now snubbed and insignificant “North” and “South” lakes in action. We had been reading old files of Hawaiian newspapers and the “Record Book” at the Volcano House, and were posted.
I could see the North Lake lying out on the black floor away off in the outer edge of our panorama, and knitted to it by a web-work of lava streams. In its individual capacity it looked very little more respectable than a schoolhouse on fire. True, it was about nine hundred feet long and two or three hundred wide, but then, under the present circumstances, it necessarily appeared rather insignificant, and besides it was so distant from us.
I forgot to say that the noise made by the bubbling lava is not great, heard as we heard it from our lofty perch. It makes three distinct sounds—a rushing, a hissing, and a coughing or puffing sound; and if you stand on the brink and close your eyes it is no trick at all to imagine that you are sweeping down a river on a large low-pressure steamer, and that you hear the hissing of the steam about her boilers, the puffing from her escape-pipes and the churning rush of the water abaft her wheels. The smell of sulphur is strong, but not unpleasant to a sinner.
We left the lookout house at ten o’clock in a half cooked condition, because of the heat from Pele’s furnaces, and wrapping up in blankets, for the night was cold, we returned to our Hotel.