CH. xxxix. GLACIERS. 4*3 



moved, are polished and grooved by the rough stones and 

 sand frozen into the bottom of the ice, just in the same way 

 as a piece of wood is scraped by the sharp iron at the 

 bottom of a plane ; and by these glacial scratches, or stria, 

 as they are called, he could tell where glaciers had been, 

 even though there was nothing else to show that ice had 

 ever existed in the country. 



Now, when he began to examine the slopes of the Alps 

 many hundred feet above the present glaciers, and also in 

 places where it is now too hot for ice to remain, he found 

 to his surprise numbers of these glacial striae and also 

 remains of huge moraines, showing that the glaciers of 

 olden time must once have been much larger and have 

 stretched farther down the valley than they do now. And 

 what was still more strange, these same marks were to be 

 seen on the Jura Mountains, on the other side of Switzerland, 

 where there are never any glaciers at present ; moreover, on 

 the Jura there were found huge blocks, some of them as 

 big as cottages, which were not made of the same materials 

 as the hills on which they rested, but were broken pieces of 

 rock such as are now only found on the Alps. 



It was clear, then, that these enormous pieces of stone 

 must have been carried right across Switzerland from the Alps 

 near Mont Blanc, and across the lake of Geneva, which is 

 1,000 feet deep, and then deposited on the Jura range near 

 Neuchatel, where one block of Alpine gneiss, called the 

 Pierre-a-Bot, as large as a good-sized cottage, sits perched 

 on a mountain 600 feet above the top of the lake. How 

 had these blocks travelled across the Swiss plains ? No flood 

 could have carried them, for they were too heavy, and be- 

 sides they were not smooth as stones are which have been 

 rolled in water, but were rough with sharp edges. Agassiz 



