Ancient Alpine Glaciers. 369 



valley of the Khone, spread across the area, now filled 

 by the Lake of Geneva and all the lowlands of Switzer- 

 land, in a vast fan-like form, a hundred and twenty- 

 five miles in width from below Geneva to the neigh- 

 bourhood of Aarau, and deposited part of its terminal 

 moraine on the slopes of the Jura behind Neuchatel, 

 2,200 feet above the level of the lake. The famous 

 Pierre a Bot, 50 feet long by 20 feet wide, and 40 feet 

 in height, forms one of a belt of moraine blocks at a 

 height of about 800 feet above the level of the lake of 

 Neuchatel. Every Alpine valley, whether in the heart of 

 the mountains, or on the northern slopes opening into the 

 lowlands of Switzerland, or on the wide plains of Italy 

 that lie between the Alps and the Po, tells the same 

 story ; and the old glacier of the Dora Baltea, about a 

 hundred miles in length, which from Mont Blanc to 

 beyond Ivrea filled the whole valley of Aosta, has left 

 on the plains of Italy a vast moraine 60 miles in 

 circumference, more than 1,600 feet in height, and in 

 places 6 or 7 miles in width. The signs of vanished 

 gigantic glaciers constantly strike the practised eye, 

 and are indeed frequently as fresh as if the glacier had 

 scarcely left the rocks before the existing vegetation 

 began to grow upon their surfaces. 



Such being the case in the Alps and other regions 

 where we are able to study the action of modern 

 glaciers in detail, we have next to inquire Is there 

 anything further to learn in regions where glaciers are 

 found on a far greater scale ? Those who have read the 

 descriptions of navigators will be aware that in Green- 

 land the average snow-line, as a whole, descends lower 

 and lower as we go northward, till at length the whole 

 interior of the country becomes covered by one snow- 

 field, which, pressing seaward from the interior, gives 



B B 



