300 K. Fetter sen — The Rise and Fall of Continents. 



fact — while mentioning the rise of land around the G-ulf of Bothnia 

 — in the following words : " Gewiss ist es, dass der Meeresspiegel 

 nicht striken hann ; das erlaubt das Gleichgewicht der Meere schech- 

 terdings nicht." 1 Supposing the centre of gravity of the earth to 

 occupy always its original place, and that the quantity of the water 

 spread over the globe remains, on the whole, unaltered, the 

 doctrine of Buch is indisputable. Meanwhile, none of these sup- 

 positions can be considered quite certain. To answer the question 

 with perfect surety, there is as yet too great deficiency in the 

 materials of research. It has been tried, therefore, very often indeed, 

 to shake the supposition of an absolute stability in the level of the 

 sea. There has been no intention hereby of course to refer any 

 alteration in the surface of the sea that bears no distinct local 

 character, to the variability of the average level. It is evident, too, 

 that a long series of risings or sinkings — throughout the different 

 geological periods — must be regarded as an uprising or subsiding 

 movement of the solid rock. Amongst other writers, James Croll 

 has narrowly discussed the question in his book, " Climate and Time 

 in their Geological Relations," 1877. He supposes the change in the 

 level of the sea to arise partly from a displacement of the centre of 

 gravity of the earth, caused by the spreading of an enormous ice-sheet 

 over one of the polar basins, and partly by the solidification of so 

 comparatively great a mass of water, as a consequence thereof. In 

 fact, the continental masses of the Northern hemisphere seem, on 

 the whole, to have risen throughout the Quaternary period, while in 

 the Southern hemisphere they have sunk. The Antarctic basin 

 being at present covered with ice on a large scale, this seems to coin- 

 cide very well with Mr. CrolPs supposition. Suppose the ice-sheet 

 constantly increasing here, the tracts of land all over the Northern 

 hemisphere must be rising continually in proportion, which is no 

 doubt the case with large tracts. If this rise of the land had ap- 

 peared quite regular, there would have been weighty reasons indeed 

 to lean to the said theory. But, according to what has hitherto been 

 observed relative to the rising and sinking of the ground at different 

 places within the Northern and Southern hemispheres, not a few 

 deviations have presented themselves, which do not coincide with 

 Mr. CrolPs doctrine. As to the east part of North America for 

 instance, Prof. Dana has proved, that the observations made there 

 do not tend to support that opinion. Furthermore, it has been con- 

 sidered a fact that a great part of the west of Greenland is at present 

 sinking. Even some parts of England, Normandy, and the coasts 

 of the North Sea, etc., are believed to be, or to have been, sinking ; 

 while, supposing that theory to be right, and that the changes in 

 the level of the water are to refer altogether to it — all those regions 

 ought, on the contrary, to have been rising constantly, and in the 

 same proportion as Scandinavia. 



Similar irregularities are to be found, it is said, even in the 



1 " It is certain that the level of the sea cannot fall, the equilibrium of the ocean 

 renders this impossible." — See Leopold von Buch's Gesammelte Schriften, Bd. ii., 

 1370, p. 504. 



