they make a huge fan-like eruption, one hundred feet high in the centre, this display, given three or four times a day, continuing about fifteen minutes. The Splendid plays a jet two hundred feet high every three hours, continuing ten minutes, and may be spurred to quicker action. The Pyramid and the Punch Bowl are geysers that have ceased operations. The former is now only a steam-jet, and the latter, on a flat mound, is an elegant blue pool, elevated several feet, and having a serrated edge. The Morning Glory Spring, named from its resemblance to the convolvulus, is a beautiful and most delicately tinted pool. The investigators of these geysers have been able to get the temperature at a depth of seventy feet within the tubes, and find that under the pressure there exerted the boiling-point is 250°. Upon this fact is based the theory of the operation of the geyser. The boiling-point under pressure at the bottom of a long tube being much higher than at the top, the expansive force of the steam there suddenly generated drives out violently the water above it in the tube, and hence the explosive spouting. YELLOWSTONE FALLS AND CANYON. The National Park, besides the extraordinary geyser and hot-spring formations exhibits the grand scenery of the Yellowstone Falls and Canyon. The Yellowstone River has its source in Bridger Lake, to the southeast of the Park, and flows northward in a broad valley between generally snow-capped mountain ridges of volcanic origin, with some of the peaks rising over eleven thousand feet. It is a sluggish stream, with heavily timbered banks, much of the initial valley being marshy, and it flows into the Yellowstone Lake, the largest sheet of water at a high elevation in North America. This lake has bays indented in its western and southern shores, giving the irregular outline somewhat the appearance of a human hand, and there are five of them, called the "Thumb" and the "Fingers." The thumb of this distorted hand is thicker than its length, the forefinger is detached and shrivelled, the middle finger has also been badly treated, and the much swollen little finger is the biggest of all, thus making a very demoralized hand. The trail eastward over from the Upper Firehole Geyser Basin comes out on the West Thumb of the lake, mounting the Continental Divide on the way, and crossing it twice as it makes a curious loop to the northward, the second crossing being at eighty-five hundred feet elevation, whence the trail descends to the West Thumb. Yellowstone Lake is at seventy-seven hundred and forty feet elevation, and covers about one hundred and fifty square miles, having a hundred miles of coast-line. The scenery is tame, the shores being usually gentle slopes, with much marsh and pine woods. Islands dot the blue waters, and waterfowl frequent the marshes. The most elevated portion of the immediate environment is Flat Mountain, on the southwestern side, rising five