Swiss Erratic Basins. 99 



tigations of M. de Charpentier, Escher, Von Derlinth and 

 Studer, and more particularly to those extensive and most 

 minute researches of Professor Guyot in Switzerland, with- 

 out speaking of my own and some contributions from visitors, 

 — as the Martins, James Forbes, and others, to justify my 

 assertion, that no important fact, respecting the loose mate- 

 rials spread all over Switzerland, has been added by the 

 advocates of currents since the days of Sanssure, De Luc, 

 Escher and Von Buch ; whilst Professor Guyot has most 

 conclusively shewn that the different erratic basins in Swit- 

 zerland are not only distinct from each other, as was already 

 known before, but that in each the loose materials are ar- 

 ranged in well-determined regular order, shewing precise 

 relations to the centres of distribution, from which these 

 materials originated ; an arrangement which agrees in every 

 particular with the arrangement of loose fragments upon the 

 surface of any glacier, but which no cause acting convulsively 

 could have produced.* 



The results of these investigations are plainly that the 

 boulders found at a distance from the Central Alps, originated 

 from their higher summits and valleys, and were carried down 

 at different successive periods in a regular manner, forming 

 iminterrupted walls and ridges, which can be traced from 

 their starting-point to their extreme peripheric distribution. 



I have myself shewn that there are such centres of distri- 

 bution in Scotland, and England, and Ireland ; and these facts 

 have been since traced in detail in various parts of the British 

 islands by Dr Buckland, Sir Charles Lyell, Mr Darwin, Mr 

 M'Laren, and Professor James Forbes, pointing clearly to 

 the main mountain groups as to so many distinct centres of 

 dispersion of these loose materials. 



Similar phenomena have been shewn in the Pyrenees, in 

 the Black Forest, and in the Vosges, shewing beyond question, 

 that whatever might have been the cause of the dispersion of 



* A comparison of the maps, shewing the arrangement of the moraines upoa 

 the glacier of the Aar, in my Stjsteme Olaciaire, with the maps which Professor 

 Guyot is about to publish of the distribution of the erratic boulders in Switzer- 

 land, will shew more fully the identity of the two phenomena. 



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