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GEYSER, GEISER, or GEISIR
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See also:GEYSER, GEISER, or GEISIR , a natural See also:spring or See also:fountain which discharges into the See also:air, at more or less See also:regular intervals of See also:time, a See also:column of heated See also:water and See also:steam; it may consequently be regarded as an intermittent hot spring. The word is the Icelandic geysir, gusher or rager, from the verb geysa, a derivative of gjosa, to gush. In native usage it is the proper name of the See also:Great Geyser, and not an appellative—the See also:general See also:term hver, a hot spring, making the nearest approach to the See also:European, sense of the word (see Cleasby and See also:Vigfusson, Icelandic See also:English See also:Dictionary, s.v.). Any hot spring capable of depositing siliceous material by the evaporation of its water may in course of time transform itself into a geyser, a See also:tube being gradually built up as the level of the See also:basin is raised, much in the same manner as a volcanic See also:cone is produced. Every geyser continuing to See also:deposit siliceous material is preparing its own destruction; for as soon as the tube becomes deep enough to contain a column of water sufficiently heavy to prevent the See also:lower strata attaining their boiling points, the whole mechanism is deranged. The deposition of the See also:sinter is due in See also:part to the cooling and evaporation of the siliceous See also:waters, and in part to the presence of living See also:algae. In geyser districts it is easy to find thermal springs busy with the construction of the tube; warm pools, or laugs, as the Icelanders See also:call them, on the See also:top of siliceous mounds, with the mouth of the See also:shaft still open in the See also:middle; and dry basins from which the water has receded with their shafts now choked with rubbish. Geysers exist at the See also:present time in many volcanic regions, as in the See also:Malay See also:Archipelago, See also:Japan and See also:South See also:America; but the three localities where they attain their highest development are See also:Iceland, New See also:Zealand and the Yellowstone See also:Park, U.S.A. The very name by which we call them indicates the See also:historical priority of the Iceland See also:group. The Iceland geysers, mentioned by Saxo Grammaticus, are situated about 30 M. N.W. of Hecla, in a broad valley at the See also:foot of a range of hills from 300 to 400 ft. in height. Within a See also:circuit of about 2 m., upwards of one See also:hundred hot springs may be counted, varying greatly both in See also:character and dimensions. The Great Geyser in its See also:calm periods appears as a circular See also:pool about 6o ft. in See also:diameter and 4 ft. in See also:depth, occupying a basin on the See also:summit of a See also:mound of siliceous See also:concretion; and in the centre of the basin is a shaft, about ro ft. in diameter and 70 ft. in depth, lined with the same siliceous material. The clear See also:sea-See also:green water flows over the eastern rim of the basin in little runnels. On the See also:surface it has a temperature of from 76° to 89° C., or from 168° to 188° F. Within the shaft there is of course a continua] shifting both of the See also:average temperature of the column and of the relative temperatures of the several strata. The results of the observations of See also:Bunsen and A. L. O. Descloizeaux in 1847 were as follows (cf. Pogg. See also:Ann., vol. 72 and Comptes rendus, vol. 19): About three See also:hours after a great eruption on See also:July 6, the temperature 6 metres from the bottom of the shaft was 121.6° C.; at 9.50 metres, 121.1°; at 16.3o metres, ro9° (?); and at 19.70 metres, 95° (?). About nine hours after a great eruption on July 6, at about 0.3 metres from the bottom, it was 123°; at 4.8 metres it was 122.7°; at 9.6 metres, 113°; at 14.4 metres, 85.8°; at 19.2 metres, 82.6°. On the 7th, there having been no eruption since the previous forenoon, the temperature at the bottom was 127.5°; at 5 metres from the bottom, 123°; at 9 metres, 120.4°; at 14.75 metres, ro6.4°; and at 19 metres, 55°. About three hours after a small eruption, which took See also:place at See also:forty minutes past three o'See also:clock in the afternoon of the 7th, the temperature at the bottom was 126.5°; at 6.85 metres up it was 121.8°; at 14.75 metres, Ire; and at 19 metres, 55°. Thus, continues Bunsen, it is evident that the temperature of the column diminishes from the bottom upwards; that, leaving out of view small irregularities, the temperature in all parts of the column is found to be steadily on the increase in proportion to the time that has elapsed since the previous eruption; that even a few minutes before the great eruption the temperature at no point of the water column reached the boiling point corresponding to the atmospheric pressure at that part; and finally, that the temperature about See also:half-way up the shaft made the nearest approach to the appropriate boiling point, and that this approach was closer in proportion as an eruption was at See also:hand. The Great Geyser has varied very much in the nature and frequency of its eruptions since it began to be observed. In 1809 and 1810, according to See also:Sir W. J. See also: During quiescence the column of water fills only the lower part of the shaft, its surface usually' lying from 9 to 12 ft. below the level of the See also:soil. Unlike that of the Great Geyser, it is always in ebullition, and its temperature is subject to comparatively slight See also:differences. On the 8th of July 1847 Bunsen found the temperature at the bottom 112.9° C.; at 3 metres from the bottom, 111.4°; and at 6 metres, ro8°; the whole depth of water was on that occasion 10.15 metres. On the 6th, at 2.90 metres from the bottom it was 114.2°; andat 6.2o metres, Io9.3°. On the loth, at o•35 metres from the bottom, the See also:reading gave 113.9°; at 4.65 metres, 113.7°; and at 8.85 metres, 99'90. The great geyser-See also:district of New Zealand is situated in the south of the See also:province of See also:Auckland in or near the upper basin of the Waikato See also:river, to the N.E. of See also:Lake See also:Taupo. The See also:scene presented in various parts of the districts is far more striking and beautiful than anything of the same See also:kind to be found in Iceland, but this is due not so much to the grandeur of the geysers proper as to the bewildering profusion of boiling springs, steam-jets and mud-volcanoes, and to the fantastic effects produced on the rocks by the siliceous deposits and by the See also:action of the boiling water. In about 188o the geysers were no longer active, and this See also:condition prevailed until the Tarawera eruption of 1886, when seven gigantic geysers came into existence; water, steam, mud and stones were discharged to a height of 60o to 80o ft. for a See also:period of about four hours, when quieter conditions set in. Waikite near Lake See also:Rotorua throws the column to a height of 30 or 35 ft. In the Yellowstone See also:National Park, in the See also:north-See also:west corner of See also:Wyoming, the various phenomena of the geysers can be observed on the most portentous See also:scale. The geysers proper are about one hundred in number; the non-eruptive hot springs are much more numerous, there being more than 3000. The dimensions and activity of several of the geysers render those of Iceland and New Zealand almost insignificant in comparison. The See also:principal See also:groups are situated along the course of that tributary of the Upper See also:Madison which bears the name of See also:Fire Hole River. Many of the individual geysers have very distinctive characteristics in the See also:form and See also:colour of the mound, in the See also:style of the eruption and in the shape of the column. The " Giantess " lifts the See also:main column to a height of only 50 or 6o ft., but shoots a thin See also:spire to no less than 250 ft. The " See also:Castle " varies in height from ro or 15 to 250 ft.; and on the occasions of greatest effort the See also:noise is appalling, and shakes the ground like an See also:earthquake. " Old Faithful " owes its name to the regu- larity of its action. Its eruptions, which raise the water to a height of loo or 150 ft., last for about five minutes, and recur every See also:hour or thereabouts. The " Beehive " sometimes attains a height of 219 ft.; and the water, instead of falling back into the basin, is dissipated in spray and vapour. Very various accounts are given of the " See also:Giant." F. V. See also:Hayden saw it playing for an hour and twenty minutes, and reaching a height of 140 ft., and See also:Doane says it continued in action for three hours and a half, and had a maxi-mum of 200 ft.; but at the See also:earl of Dunraven's visit the eruption lasted only a few minutes. Theory of Geysers.—No satisfactory ex-planation of the phenomena of geysers was advanced till near the middle of the 19th See also:century, when Bunsen elucidated their nature. Sir George Mackenzie, in his Travels in Iceland (2nd ed., 1812), submitted a theory which partially explained the phenomena met with. " Let us suppose a cavity C (fig. I), communicating with the See also:pipe PQ, filled with boiling water to the height AB, and that the steam above this See also:line is See also:con-fined so that it sustains the water to the height P. If we suppose a sudden addition
of See also:heat to be applied under the cavity C, a quantity of steam will be produced which, owing to the great pressure, will be evolved in starts, causing the noises like discharges of See also:artillery and the shaking of the ground." He admitted that this could be only a partial explanation of the facts of the case, and that he was unable
259°
Palestinian cities and the Gazri of the Amarna tablets), a royal Canaanite See also:city on the boundary of See also:Ephraim, in the maritime See also:plain (Josh. xvi. 3-ro), and near the See also:Philistine border (2 Sam. v. 25). It was allotted to the See also:Levites, but its See also:original inhabitants were not driven out until the time of See also:Solomon, when " See also:Pharaoh, See also: See also:Josephus also mentions that the city was " naturally strong " (Antiq. viii. 6. I). The position of Gezer is defined by See also:Jerome (Onomasticon, s.v.) as four See also:Roman See also:miles north (contra septentrionem) of Nicopolis (`Amwas). This points to the mound of debris called Tell-el-Jezari near the See also:village of See also:Abu Shusheh. The site is naturally very strong, the See also:town See also:standing on an isolated See also: Macalister's reports in Palestine Exploration Fund Quarterly Statement (See also:October 1902 onwards). Also See also:Bible Sidelights from the Mound of Gezer, by the same writer. (R. A. S. Additional information and CommentsThere are no comments yet for this article.
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