788 GEYSERS ter, immediately after which the water bursts forth in a succession of jets, apparently 6 ft. in diameter at the bottom, and tapering to a point at the top, to a height of from 175 to 200 ft., while the steam ascends to 1,000 ft. or more. This immense body of water is kept up to this height for about 20 minutes, when it gradually recedes and again becomes quiescent. On the opposite side of the river is the Castle, so called from its resemblance to the ruins of a tower. It stands upon a platform measuring 75 by 100 ft. and 3 ft. in height, above which it rises about 12 ft. Prof. Ilayden witnessed three eruptions of this geyser in 1872. The maxi- mum height of the first was 34 ft., and of the second 93 ft. ; that of the third was not ascer- tained. The eruptions lasted each about an hour and 20 minutes. The Giant geyser has a rugged crater, like a broken horn, 10 ft. in height and 24 by 25 ft. at the base. The top is about 8 ft. in diameter, with an irregular orifice of 5 or 6 ft. in width. The cone is open The Giant Geyser. on one side, having a ragged aperture from the ground upward. Its discharges are irregu- lar, and continue for irregular periods. When Prof. Hay den saw it in 1871, it played an hour and 20 minutes, throwing the water 140 ft. ; but Lieut. Doane, who visited it the year be- fore, states that it played 3 hours at one time, to a height varying from 90 to 200 ft. The Grotto, the Punch Bowl, the Riverside, the Soda, and the Fan geysers, and numerous others which have not yet even been named, merit notice. There are wonderful groups also on the S. W. side of Shoshone lake, the head of one of the principal forks of the Shoshone or Snake river; and on Gardiner's river are some of the most remarkable springs in the world. The springs in action among the latter are not so numerous nor so powerful as those of the Fire-Hole basin, but are far more won- derful in their calcareous deposits, which ex- ceed even those of the New Zealand geysers. In one place a hill 200 ft. high has been formed in a system of terraces, ornamented with semi- circular basins, and with beadwork of beau- ful colors on a snow-white ground. These calcareous deposits cover an area of about two miles square. The active springs extend from the margin of the river to an elevation of 1,000 ft. above, the highest being 6,522 ft. above the sea. The geysers of the Fire-Hole basin are from 6,800 to 7,000 ft. above the sea. The valley of the Madison, with its branches, is shut in by high volcanic mountains, gashed with deep gorges, strewn upon their sides and at their bases with fragments of trachyte and obsidian, and covered with tall pines. Be- tween the sources of the Madison and the Yellowstone these mountains rise to 9,000 or 10,000 ft. above the sea. The valley of the Fire-Hole river is covered with the silicious deposits of the springs, and resembles an al- kali flat. The bed of the stream is lined with white silica. Beneath this formation are lake or local drift deposits, and still lower basalt. The surface deposit is chiefly geyserite. The most of it is of an opaque white color, but in the lower basin pink specimens are found which are translucent. Some of it is greenish gray and some pearly, like enamel ; and it assumes forms similar to those in Iceland. Some have a cauliflower-like form, and break very easily ; others are beaded, and others covered with small stalagraitic processes. The texture varies from porous to compact, the most being porous and arranged in layers. The geyser cones are generally compact, and often have an enamel- like coating. A specimen of the white gey- serite, of cauliflower form, contained silica 83-83, water 11-02, chloride of magnesium 4; total, 98-85. The water contains very little solid matter. A specimen brought back by Dr. Peale was as clear as when bottled at the springs, showing no deposit ; it contained 835f f milligrammes of solid matter to the litre, consisting mainly of silica; chloride of lime and sulphate of magnesia were present in small quantity, and there was a slight trace of iron. The geysers of Iceland are treated of in "Letters on Iceland," by Von Troil (1772); " Travels in Iceland," by Sir George Mackenzie (1810); "Journal of a Residence in Iceland during the years 1814 and 1815," by Ebenezer Henderson; " Visit to Iceland in the Summer of 1834," by John Barrow, jr. ; " A Visit to Iceland," by the Hon. A. Dillon (1840); ob- servations of M. Descloiseaux in Annales de chimie et de physique (April, 1847), and " Philo- sophical Magazine" (vol. xxx. p. 397); "Tracings of Iceland and the Faroe Islands," by R. Cham- bers (1856) ; " A Yacht Voyage," by Lord Duf- ferin (London, 1858) ; " Iceland, its Scenes and Sagas," by Sabine Baring-Gould (1863) ; " The Land of Thor," by J. Ross Browne (1867) ; and "A Summer in Iceland," by C. W. Paijkull, translated from the Swedish by the Rev. M. R. Barnard (1868). For an account of the New Zealand geysers see Neu-Seeland, by Fer- dinand von Hochstetter (Stuttgart, 1863). For
