328 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



The essential fact is this, that all along the great mass of mountains 

 which extends through Southern Europe to the Caspian Sea, including the 

 Pyrenees, the Alps proper, and the Caucasus, the glaciers liave been dimin- 

 ishing in size with considerable regularity during the last few years. While, 

 however, the recession seems now to be general, and to extend through from 

 the Atlantic to the Caspian, it is certain that it did not begin through the 

 whole region at precisely' the same time. Indeed, portions of the Alps not 

 far distant from each other took up the receding movement at quite differ- 

 ent periods. 



Of the four great glaciers near Chamouni — des Bois, des Bossons, du Tour, 

 and d'Argentiere — the first one mentioned seems to have been receding 

 during the longest period, and to have been most shortened. According to 

 Venance Payot, it had lost in length from 1818 up to October 8, 1880, no 

 less than 1,250 meters. Between the 25th of March and the 3d of June, 

 1880, or in seventy days, it had receded ten meters. Between June and 

 October of that year it remained nearly stationary. The Glacier d'Argen- 

 tiere has diminished during the past lew years more rapidly tlian any other 

 of the four, and between June 28th and November 15th, 1880, it had receded 

 a little more than forty meters. 



The Glacier des Bossons had diminished in length between 1817 and 

 June 12, 1874, no less than G82 meters, and its recession at that time was 

 becoming more and more rapid, having been as much as twenty-seven meters 

 a year, on the average, between 1862 and 187-1. This glacier, in 1880, had 

 become very irregular in its movements, one side receding and advancing 

 irregularly, and not synchronously with the central portion. M. Payot 

 remarks that during the month of May, 1880, the glacier seemed to be 

 undergoing some internal movement which went on without ceasing. 

 Kollini!; and crackinii; sounds were heard continunllv, and masses of ice were 

 constantly falling from the front of the mass, so as to render access very 

 dangerous. 



The shrinking of the glaciers on the north slope of the Mont Blanc 

 system seems to have been first noticed during the years 1818 to 1828 ; 

 from that latter date on, it began to be recognized as general. At 

 the close of the season of ISSO M. Payot seemed satisfied, from \arious 

 appearances in and about the glaciers of that region, that the period of 

 recession was about to come to an end, and that a forward movement was 

 soon to begin. He says : " The freriuency of avalanches, the foi-mation of 



