T. F. Jamieson — the Scandinavian Glacier. 391 



2. Again, Dr. Tyndall reminds us that what we most want in 

 order to produce the glaciers of the Tee-time is improved condensers. 

 Now there is no better condenser that a lofty mountain. Heave it 

 high enough and you will get snow at the Equator, as we see on the 

 Andes, and at Kilima-Njaro in Africa. Here then we have another 

 good argument for a much greater height of the Scandinavian 

 plateau, and the same observation will hold good for other glaciated 

 regions. I therefore think that at the commencement of the Ice- 

 time these countries had a far greater altitude than at present — an 

 opinion which I expressed quite as distinctly thirty years ago.^ It 

 is difficult, indeed, to see how otherwise a sufficient permanent 

 condensing power could have been sustained in these latitudes ; for 

 even in Greenland, at the present day, the line of perpetual snow 

 is 2000 feet above the sea-level, and it is on the high mountain range 

 of the interior that the ice is generated. Dr. Croll,'^ in his paper on 

 the Antarctic ice, asserted that " the Greenland ice-sheet, like the 

 Antarctic, must be thickest at the centre of dispersion and thinnest 

 at the edge." If the ice lay upon a perfectly flat horizontal plane, 

 no doubt it would require to be thickest at the centre, but if the 

 ground supporting it is 10,000 or 15,000 feet higher at the centre 

 than at the edge, as seems not unlikely, then the thickness at the 

 centre of dispersion need not be so very great. If Croll had said 

 that the surface of the ice-sheet must be Jiighest at the centre and 

 lowest at the edge, it would have been all very well ; but the thickness 

 of the ice at the centre of dispersion must depend much upon the 

 altitude of the surface on which the ice rests. 



As the ice accumulated upon these lofty regions they appear to 

 have gradually undergone a movement of depression, and the opinion 

 seems to be gaining ground that this depression may have been 

 caused by the weight of ice which was laid upon them.^ It is at 

 any rate quite clear that after the period of maximum glaciation 

 Scandinavia underwent a partial submergence, during which the 

 great glacier seems to have broken up and disappeared from much 

 of the ground it once covered, and this same order of events seems 

 to have occurred in the other great centres of glaciation in Britain 

 and North America. 



Dr. Penck's* theory that the submergence was caused by attraction 

 of the ice drawing the sea up on to the land, has not been sustained 

 by an appeal to mathematical investigation ; for Woodward in 

 America, Drygalski, and Hergesell in Germany, and Faye in France, 

 who have in elaborate papers discussed the subject from a mathe- 

 matical point of view, seem all to agree that the cause in question 

 would be quite insufficient to account for the facts, even on the most 

 liberal estimate of the possible volume of ice. Indeed, it would 



1 Quart. Journ. Geol. Soc. vol. xviii. p. 180-1, Feb. 1862. 



^ Quart. Journ. of Science, Jan. 1879. 



^ G. de Geer, Om Skandinaviens Nivaforandringar under Quartarperioden. Stock- 

 holm, 1890. Warren XJpham, Eeview of the Quaternary Era, Amer. Journ. of 

 Science, Jan. 1891. 



* Schwankungen des Meeresspiegels, Jahrb. der Geog. Ges. zu Munchen, 

 bd. vii. 1882. 



