I IO JOURNAL OF SCIENCE. 



at the pole, and the moan attraction of the moon being in the plane of 

 the ecliptic, its tendency would be to draw the mass towards the ecliptic 

 — so far, at least, until an equilibrium should be found. 



"That the relative magnitudes of the two polar ice-sheets should 

 always remain the same, would hardly be presumed. The sinking of 

 the ice to the bottom of the Northern Atlantic would necessarily cut off 

 the Gulf Stream, and prevent its further progress northward, if it 

 existed in preglacial times. Even if the ice extended only a few 

 hundred feet below the surface, it would materially interfere with that 

 current, since it is a broad shallow stream, flowing upon the top of the 

 ocean. Similar conditions in the southern ocean might have aided the 

 causes already named in effecting a change or changes in the relative 

 sizes of the two great glaciers. During such changes, therefore, if any 

 existed, oscillations of the earth's axis may have occurred before it 

 became fixed as at present. We should therefore expect to find pauses 

 in the recession, and perhaps a re-advance, of the northern glacier ; and 

 such we do actually find from an examination of the great Kettle 

 Moraine in the northern United States, and of the I'eindeer epoch in 

 Europe. 



"As already stated, the ocean-level would be very materially 

 lowered. Thus we can account, in part at least, for the land elevations 

 in high latitudes, to which all geologists resort for a partial explanation 

 of glacial phenomena. True, this lowering of the level would be co- 

 extensive with the entire ocean surface ; and the old shore-lines would 

 be found, if discovered at all, below the present water-level. But, as 

 Professor Dana says, ' elevations of land do not leave accessible records 

 like subsidences.' One of the strongest evidences of land elevation is 

 the existence of numerous extensive fiords, which Professor Dana says 

 are ' valleys of erosion,' and which Professor Le Conte calls ' half-sub- 

 merged glacial valleys.' But, as the ice did not exist at sea-level in low 

 latitudes, these fiords are not found there as fossil remains to mark the 

 degree of elevation. But we know that England was united to the 

 continent of Europe by dry land, that the Mediterranean sea was an 

 interlocked fresh-water lake, that the delta of the Mississippi was at 

 least 400 feet higher than it is at present, and that many of the islands 

 of the Pacific Ocean were at a higher level. Professor Winchell, in his 

 ' Pre- Adamites,' says that probably the now sunken continent of 

 Lemuria, in the Indian Ocean, was dry land during the glacial period, 

 as were also some of the Malay Islands and others. Professor Le Conte 

 says, ' The boldness of the whole Pacific coast, especially in high lati- 

 tudes, indicates a previous more elevated condition of the land surface 

 [during the quaternary] than now exists ;' and Mr. Darwin thinks that 

 ' at this period of extreme cold the climate under the equator at the 

 level of the sea was about the same with that now felt there at the 

 height of six or seven thousand feet.' 



" Moreover, if this inequality in the amount of the accumulation 

 at the two poles existed as intimated, it would be sufficient to remove 

 the centre of gravity of the earth a little to the southward of its former 

 position. This would be followed by a greater flow of water from the 

 north polar regions ; and here we would have another cause ot land 

 elevation in high northern latitudes, since lowering the water is equiva- 



