July 8, 1898.] 



SCIENCE. 



41 



explain the much greater ravines by which 

 the edges of continental shelves are so often 

 notched. The Ehone, entering Lake Ge- 

 neva, is visible for a little distance by its 

 M^hitish color in the clear water of the lake; 

 but it suddenly sinks and disappears about 

 500 feet out from its mouth. Judging by 

 the texture of bottom deposits along the 

 path of the descending river, its velocity 

 at a distance of 7 kilometers from the head 

 of the lake and at a depth of 250 meters 

 must be 0.20 m. a second. 



LAKES OF THE AUSTRIAN ALPS. 



The text by Eichter to the second part 

 of the Atlas der dsterreichischen Alpenseen 

 (1896) appears in the Geographische Ab- 

 handlungen, edited bj^ Professor Penck, of 

 Vienna (Vol. VI., Xo. 2, 1897). It de- 

 scribes and explains the origin of the 

 lakes and gives a detailed discussion of 

 their temperatures. The lakes of the Drave 

 basin are ascribed rather to barriers of 

 drift and torrent fans than to glacial action, 

 thus giving another example of the differ- 

 ent conclusions as to the competence of 

 glacial erosion reached by detailed local 

 study and by generalizations at a distance. 

 The Millstatter See, for example, is cut off 

 from the aggraded valley of the Drave by 

 the torrent fan of the Lieser. Two 

 small lakes, Afritzen and Brenn, are similar 

 in origin to the lakes of the upper Inn, 

 which were explained som.e years ago by 

 Heim as the indirect result of the capture 

 of headwaters of the Inn by an encroaching 

 Italian stream. Several of the deeper 

 lakes show a slight rise of temperature in 

 the bottom waters during the spring 

 months, which E-ichter explains as the re- 

 sult of conduction of the heat from the 

 earth's crust after the active cooling of the 

 surface waters in winter has ceased. 



THE LOB NOE CONTEOVEESY. 



Undee the above title, the (London) 

 Geographical Journal for June, 1898, contains 



an account, based chiefly on the work of 

 Eussian explorers, of the shallow lakes in 

 the desert basin of Eastern Turkestan. The 

 point at issue is : Which one of the several 

 lakes of the region shall be identified as the 

 Lob Nor of the Chinese maps ; no lake 

 being called by this name among the people 

 of the region. This controversial matter is 

 of less general interest than the phj'sical 

 features which are so well adapted to lead 

 to controversy. A vast barren aggrading 

 plain of sand and clay, occupying a great 

 basin between enclosing mountains ; fickle 

 rivers which run far forward in flood and 

 wither away in drought, occasionally turn- 

 ing into new channels and wandering a 

 hundred miles from their abandoned beds ; 

 wandering sand dunes and growing deltas, 

 disputing possession of the faint depressions 

 with extensive reedy marshes and shallow 

 shifting lakes ; the lakes now brackish, 

 now salt, at one time expanding, at another 

 shrivelling ; even the villages of uncertain 

 mind, deserting an old site for a new one 

 when invaded by dune, marsh or lake. A 

 centenarian told one of the Eussian ex- 

 plorers that he would not have recognized 

 the country of his boyhood if he had re- 

 turned there in his old age after spend- 

 ing his life abroad. Controversy naturally 

 arises in such a geographical environment. 

 It would then be with a new meaning 

 that the returning traveller would sing : 

 ' There's no place like home.' 



lake mendota. 

 The use of lakes as biological stations by 

 our inland universities promotes their phys- 

 ical exploration. The account of Turkey 

 Lake, already noted in Science, is now fol- 

 lowed by ' Plankton Studies on Lake Men- 

 dota,' by Birge (Trans. Wise. Acad. Sci., 

 XI., 1897, 274-448, of which 286-300 are on 

 lake temperatures) . The depth of the lake 

 is 18 meters. In May there is a rapid gain 

 of heat through the whole water body ; dur- 



