GLACIERS IX OTHER PARTS OF THE WORLD. 105 



more than 7,500 feet above the sea. The glaciers extend, 

 from 4,000 to 5,000 feet lower, though the limit is by no 



Fig. 36.— "Morteratsch Glacier. Orisons Alps. This glacier advances about seven inches 

 per year. Centuries ago chalets stood a mile farther up the valley. In 1868 frag- 

 ments of these ancient dwellings were washed out from underneath the ice. 



means constant from year to year. " M. Forel reports, from 

 the data which he has collected with much care, that there 

 have been in this century five periods in the Alpine glaciers : 

 of enlargement, from 1800 (?) to 1815 ; of diminution, from 

 1815 to 1830 ; of enlargement, from 1830 to 1815 ; of dimi- 

 nution, from 1S15 to 1875 ; and of enlargement, again, from 

 1875 onward. He remarks further that these periods cor- 

 respond with those deduced by Mr. C. Lang for the variations 

 for the precipitations and temperature of the air ; and, con- 

 sequently, that the enlargement of the glaciers has gone for- 



