Continuing our trip southward through Gibbon Cañon and by Gibbon Falls, whence the landscape is more level, we came at length to Fire-Hole Creek and the Lower Geyser Basin. We were now in the region of giant geysers, in the visible presence of the most terrible manifestations of nature. In this pit of Acheron, this purgatory of ferment and explosion, covering an area of forty square miles, are almost countless geysers, distributed in seven groups, as if banded in rivalry. One of these groups is near the center of the basin and has one hundred orifices that spout steam and water, resembling from a distance an extensive manufactory. The most interesting feature of the Lower Basin is Fountain Geyser, which throws a column of water twenty feet in diameter to a height of fifty feet, though it plays only at intervals of many days. Near-by is Monument Basin, so called from the formations of every conceivable shape which distinguish it. Evangeline Geyser is another eruptive volcano that throbs and thumps violently when in action, but never casts up water more than a few feet above the surface; it has a beautifully scalloped rim, with small bowls of exquisite incrustations, resembling some of the basins in Mammoth Terraces. It is in the Upper Basin, eight miles further south, however, that the greatest of geysers are to be seen, though the area covered is scarcely three square miles, and the springs are less numerous. In this region, very near to Fire- Hole River, is a spot called Hell’s Half-Acre, a designation peculiarly appropriate by reason of the purgatorial wonders which exist therein, and the activity with which old Nick’s stokers stir the subterranean furnaces. The largest geyser in this fiery-haunted district, and indeed much the largest in the world, is Excelsior Geyser, which has a mouth two hundred feet wide and has been known to cast up a flood of water two hundred feet high, carrying with it large stones rent from the walls of its Plutonian caverns. Excelsior displays its power at very rare intervals, sometimes remaining quiet for years; but to our surprise and joy it was in a state of violent eruption during our visit, and thus gave us an opportunity not only to see but to photograph its immensity and awfulness. ------------------------------------------------------------------------ [Illustration: EXCELSIOR GEYSER IN ACTION.—Excelsior is the largest geyser, not only in Yellowstone Park, but in the whole world. Its mouth is 200 feet wide, and it has been known to spout a volume of hot water 200 feet high and filling the entire space of its cavity, carrying with it large stones rent from the interior of the earth. Such displays of its power occur only at rare intervals, but fortunately it was in a state of violent eruption at the time of the visit of our photographing party, and they thus had an opportunity not only to see but to photograph this wonder of nature in its immensity and awfulness. ]