JrxE 21, 1895.] 



SCIENCE. 



079 



ological oliservatioiis on the Eiii'el tower 

 during 1S92 ; and by Durand-GrevilK' ou 

 squalls aud thunderstorms. Nearly all the 

 features of the advance of vegetation exhil)it 

 the accelerating influence of the Mediter- 

 ranean and the retarding influence of the 

 Bay of Biscay. The records of the Eift'el 

 tower are chiefly interesting in showing in- 

 versions of nocturnal temperature in the 

 means of all the months, aud consequently 

 iu proving a distinct variation in the diurnal 

 values of the vertical temperature gradient 

 in the lower atmosphere: as well as a change 

 of the time of maximum wind velocity from 

 afternoon at surface stations to night at the 

 top of the tower. Durand-Greville's essay 

 is illustrated by an excellent chart of the 

 distribution of pressure during an extended 

 squall that occurred on August 27, 1890; 

 the isobars being drawn for every milli- 

 meter, and showing a sharp N-like double 

 bend at the place of the s(iuall. 



WINTER STORMS IX THE XORTH SE.\. 



The famous Christmas storm of 1821, 

 which led Braudes and Dove to their 

 early statements concerning the system of 

 storm winds, finds a modern parallel in a 

 storm of December 22-23, 1894, described 

 by Koppen in the Annalen der Hydrographie , 

 edited by the Xaval Observatory at Ham- 

 burg, and published in Berlin. On the moi'u- 

 ing of December 22 the storm center, with a 

 pressure of 715 mm., lay just east of Scot- 

 land ; on the evening, with a pressure of 

 72.5, the center lay just west of Denmark. 

 The whirling courses of the winds are well 

 illustrated ; a soutlierly gale crossed the 

 Baltic, while a northerly gale raged on the 

 North sea; violent east winds blew off the 

 coast of Norway, and westerly gales were 

 recorded in northern Germanj-. Disastrous 

 storm floods were felt at manj' points on 

 the coast, and salty rain fell at many points 

 in England. Other storms were felt a week 

 earlier and later ; but, aprojtos of thi.s ap- 



I)arent periodicity. Kijppen remarks that 

 thus fiir all eflbrts to establish weekly, 

 monthly or longer weather cycles have, 

 without exception, failed, and that, while 

 the faint and easily obliterated traces of 

 such periods have a certain .scientific in- 

 terest, they have not yet a practical value. 

 The Anncden der Hydrographie is a character- 

 istic German journal, in which a serious 

 aud scientific stjde of work is carried into 

 the accounts of foreign coasts and harltore, 

 as reported by ofticers of the marine. It 

 frequently contains articles and reviews of 

 interest on winds, tides and currents. 



ELEV.A.TIOX AS A C-'VUSE OF GLACI.\TION. 



It is probable that uo one questions the 

 sufficiency of elevation to account for gla- 

 ciation, if other things, such as external 

 controls of climate, remain unchanged; but 

 there are serious difficulties in the way of 

 accepting the thesis maintained by Upham 

 (latest expressed in Bull. Geol. Soc. Amer., 

 vi., 1S95, 343-3.52) to the effect that 

 the glacial sheets of northeastern America 

 and northwestern Europe were caused by 

 and hence were coincident in time with the 

 elevation that permitted the erosion of the 

 deep marginal valleys of the continents. 

 Upham cites the ca.se of the Sogne fiord, on 

 the west coast of Norway with a maximum 

 sounding of 4.080 feet, as a measure of the 

 epirogenic uplift which at its culmination 

 caused the glaciation of northern Europe. 

 The difficulty here is that while a compara- 

 tivelj' long period of elevation must be pos- 

 tulated for the excavation of the valley of 

 Sogne fiord, and while climatic change 

 would respond immediately to elevation, 

 yet glacial conditions are not known to 

 have occured until the erosive eftects of 

 elevation were practically completed. The 

 steepness of the fiord walls indicates that 

 the elevation was not slowly progressive, 

 but was rather promptly comjileted and 

 steadily maintained ; being in this unlike 



