114 Esmark on the Geological History of' the EartJi. 



masses of rock which are found about Geneva^ and the coast of 

 the Baltic, and the formations of the vast sand-plains which are 

 found in Holland and in the north of Germany, infers that not 

 only strong currents, but ice likewise, must have had a share in 

 producing these effects*. Tl^ere are not wanting many facts to 

 confirm the conclusion that ice has worked prodigious changes 

 on mountain masses, and conveyed from them large rocks into 

 regions, where now no perennial ice is to be found, at a great 

 distance from the mountains, from which they must have come. 

 Men have often had recourse to extraordinary exertions of the 

 powers of nature in explaining these phenomena. Thus has 

 De Luc endeavoured to account for them by the eruption of 

 gaseous fluids from the bowels of the earth, which have burst 

 the mountains, and scattered the loosened fragments to a 

 great distance around. The huge masses of granite which are 

 to be found on the limestone mountains of the Jura range, 

 and which have evidently come from the Alps of Switzerland^ 

 though there lie deep valleys between the Alps and the Jura 

 mountains, have been a riddle to many, especially as they are 

 found very high up on the slope of the hills, and not in the 

 bottom of the valley. Some, as I have mentioned, wish to ex- 

 plain this by a projectile power. Dolomieu imagines that there 

 has been formerly a continued slope from the top of the Alps to 

 the Jura hills, on which these rocky masses have descended 

 from the one to the other, and that the present intervening val- 

 leys have been hollowed out by more recent revolutions. A few 

 suppose that these masses have been brought to their present 

 situation by ice. According to Von Buch this is a very general 

 opinion in Switzerland. It is not only in mountainous regions 

 we find this phenomenon, but also in flat alluvial districts, 

 where these rocky masses lie upon gravel and sand, a circum- 

 stance which cannot be explained in any other way, than by 

 their having been brought thither in combination with masses of 

 ice. It cannot be admitted that they could be brought to such 

 situations by torrents of water, for the same torrents which 

 could have been capable of bringing such masses of rock, 

 must at the same time have carried off* the gravel and sand 



• Vide Sir James Hall's Memoirs, in the Transactions of the Royal Society 

 of Edinburgh. 



