NA TURE 



[ June 26, 1! 



expected were they due to the progressive evaporation of 

 the large original lake. 



In tracing back the history of this interesting topo- 

 graphy, we are first brought face to face with the fact that 

 the area of the Great Basin has within recent geological 

 times been subject to powerful and long-continued sub- 

 terranean movements. In numerous cases, rocks have 

 been fractured and displaced to an extent of 4000 or 

 5000 feet. So recent are some of the fractures that they 

 actually cut through the alluvial cones that stream out 

 from the base of the mountains, and in numerous in- 

 stances displace the terraces of the old lake to the extent 

 of 50 or 60, or sometimes even 100 feet. There seems no 

 reason to dispute the conclusion to which Mr. Russell 

 and his colleagues have come, that the movements are 

 actually still in progress, and that the constant occurrence 

 of hot springs along the lines of recent fracture may be 

 taken as evidence of the conversion of the subterranean 

 movement into heat. 



What may have been the topography of the region 

 before the first depression and isolation of the Great 

 Basin is still unknown. Doubtless the ground had un- 

 dergone extensive denudation as well as great subterra- 

 nean disturbance. Considerable irregularities of surface 

 would also necessarily be produced by the intermittent 

 discharge of volcanic rocks. When this uneven floor 

 sank below the level of the surrounding tracts so as to 

 become a basin of inland drainage, a magnificent series 

 of lakes was established. Of these the largest, to which 

 the name of Lake Bonneville has been given, and of 

 which the Great Salt Lake is the diminished representa- 

 tive, covered an area of not less than 19,750 square miles. 

 Lake Lahontan was of hardly inferior dimensions, these 

 two hydrographic basins occupying the whole breadth of 

 the Great Basin in the latitude of the 41st parallel. 

 No fewer than fifteen other smaller basins have been dis- 

 covered, which, though now either dry or partially covered 

 with saline or alkaline waters, were well-filled lakes at a 

 former period. 



It is some years since Mr. Gilbert, from a study of the 

 deposits left by Lake Bonneville, announced his conclu- 

 sion that they bear testimony to a remarkable oscillation 

 of climate between humidity and aridity. Similar deduc- 

 tions have now been drawn from the deposits of Lake 

 Lahontan. Previous to the appearance of this body of 

 water the climate is believed to have been at least as dry 

 as it is at present, when alluvia] cones were pushed out- 

 wards from the base of mountains into the area of the 

 future lake. Then came a moist period, when the hollow 

 of Lahontan was filled up with water to a depth of 500 

 feet above its present desiccated floor in the Carson 

 Desert. At or about this height the water must have 

 stood a long time, for it has deposited, along its rocky 

 margin and round its islets, a thick mass of calcareous tufa. 

 That the water, if not fresh, was at least not so saline as 

 to be inimical to life, is shown by the abundant occur- 

 rence in it of fresh-water gasteropods. An epoch of 

 aridity ensuing, the lake fell to so low a level as to become 

 intensely bitter and alkaline, depositing thickly along its 

 margin crystals, six or eight inches long, of gaylussite (a 

 hydrated carbonate of soda and lime). The soda of these 

 crystals having been subsequently removed, the deposit 

 is one of tufa, mainly composed of calcareous pseudo- 

 morphs after gaylussite. Next followed a period of in- 

 creased precipitation, when the lake rose to within 200 feet 

 of its highest level, and when the thickest and most abun- 

 dant of the tufa deposits of the region was laid down 

 to a depth of sometimes 20 or even 50 feet. This third 

 incrustation of tufa was formed mainly along the rocky 

 shores and islands ; but curious mushroom-like protuber- 

 ances of it likewise gathered upon stones lying on the 

 floor of the lake. The water then rose to the highest level 

 it ever reached, since which time the climate has again 

 become arid. From the fact that the isolated lakes of 



the Lahontan Basin are not the saturated alkaline and 

 saline solutions which they would certainly have been had 

 they resulted from the evaporation of such a sheet of 

 water as that in which the three tufa terraces were elabo- 

 rated, it is inferred that the whole of the original lake 

 was evaporated to dryness, and that its alkalies and salts, 

 having been precipitated at the bottom, were covered 

 over with a layer of mud so as to be partially protected 

 from rapid solution. The existing lakes may thus be 

 supposed to be the result of a subsequent diminution of 

 the extreme aridity, but the time within which they have 

 been in existence has not been long enough to enable 

 them to become as bitter and saline as the original lake. 



Such are some of the views which renewed exploration 

 of this weird region has suggested to the able surveyors 

 who have undertaken its investigation. Mr. Russell's 

 report, lucid and interesting as it is, must be regarded 

 as merely a prelude to the fuller results which he and his 

 colleagues are gathering for the good of science, and to 

 the credit of the admirably organised and administered 

 Geological Survev of the United States. 



NOTES 

 Prof. Flower, F.R.S., will preside at a meeting which it is 

 proposed' to hold on Tuesday next, July I, in the lecture-room of 

 the Natural History Museum, when Mr. R. Bowdler Sharpewill 

 read a paper on the expediency or otherwise of adopting trino- 

 mial nomenclature in zoology. Many British naturalists have 

 been anxious to meet the distinguished American naturalist, Dr. 

 Elliott Coues, who is now on a visit to this country, and to ex- 

 change views with him on the subject of nomenclature. Invita- 

 tions have been sent to a large number of the leading British 

 zoologists, and an interesting discussion is expected. 



The Prince of Wales, President of the City and Guilds of 

 London Institute, opened the Central Institution, Exhibition 

 Road, yesterday afternoon at four o'clock. The Education Sec- 

 tion of the International Health Exhibition, in the south wing 

 of the Central Institution, was opened at the same time. 



The following additional donations to the Equipment Fund 

 of the Central Institution of the City and Guilds of London In- 

 stitute have been voted in response to the appeal of the Prince of 

 Wales: — The Goldsmiths' Company, 4000/. (subject to confir- 

 mation) ; the Salters' Company, 525/. ; the Cordwainers, 250/. 

 The -Plaisterers have increased their annual subscription from 

 50 guineas to 100/. 



It is stated that the English Foreign Office is endeavouring to 

 obtain the co-operation of the German Government in the Inter- 

 national Educational Conference to be held at the South Ken- 

 sington Health Exhibition about the middle of August. The 

 Committee attaches special importance to the attendance of 

 representative German pedagogues (this word being used in the 

 higher and German sense) at this conference to read or commu- 

 nicate papers especially on the subjects of technical and secondary 

 education and the organisation of universities ; and it is particu- 

 larly anxious to know, as early as possible, the names of any 

 Germans of note who may be disposed to attend, and the subjects 

 likely to be selected for papers. 



A large and influential deputation, including the Earl of 

 Rosebery, the Earl of Fife, Mr. Stephen Williamson, M.P., 

 Hon. R. P. Bruce, M.P., Prof. Cossar Ewart, Prof. Mac- 

 intosh (St. Andrew's), a number of Scotch M.P.'s, and other 

 gentlemen, waited last Monday on the Home Secretary with the 

 view of impressing on the Government the importance of granting 

 further funds to the Scottish Fishery Board to further scientific 

 investigation into the habits of herring and other food fishes. 

 The principal lines of proposed inquiry are: (1) The examina- 

 l ion of the spawning beds around the Scottish coast with the 



