NORWEGIAN GLACIERS, 97 



glaciers, in general similar, but differing in their exposure or 

 slope, might be very differently removed from their respective 

 equilibrium forms, and would therefore respond at different times 

 to a given climatic change; indeed, one of them might be so far 

 removed from its equilibrium form that a climatic change lasting 

 for several years might not be long enough to reverse the con- 

 dition of retreat or advance in which it happened to be" (The 

 Mechanics of Glaciers, p. 927). 



As a further demonstration of this very phenomenon we 

 are to compare the oscillation of four glaciers, the Buerbræ, the 

 Bondhusbræ, the Boiumbræ and the Briksdalsbræ, during the 

 latter half of the nineteenth century. 



The Glacier of Buer, as already mentioned, was increasing 

 somewhat rapidly about the middle of the nineteenth century, 

 but in 1860, according to statements made by Sexe, had already 

 been decreasing for some few years. This decrease seems to 

 have continued down to the year 1868. From that year a gene- 

 ral increase is reported to have taken place in this glacier down 

 to the year 1893; but this increase did not proceed in an alto- 

 gether uniform manner, as on two occasions the glacier was sub- 

 jected to a rather violent rush of extraordinary advance. The 

 first of these rushes took place in the years 1870 — 1872, and the 

 other in the years 1878 — ^1879. During recent years, from 1894 

 down to the present year, this glacier has decreased considerably. 

 This decrease is reported to have been somewhat greater in 1896 

 and 1897 than during the other years. In September last, Got- 

 SKALK Gjerde, a guide in Mauranger, informed me, that the 

 Glacier of Buer has been decreasing for several years; during 

 the present year the decrease has been somewhat less, however, 

 than during the previous years. 



The Glacier of Bondhus in 1845 had somewhat decreased. 

 In 1851, however, Forbes states that this glacier „is now gaining 

 ground ah-esh, driving a little moraine of five or six feet high 

 before it." The history of the oscillations of this glacier for the 



Nyt Mag. f. Naturv. XXXIX, II. 7 



