LECTURES. 55 



view. Hitherto, the theories respecting the geologi- 

 cal formation of the earth, as held by Werner, were 

 that all this material had been brought together by 

 water and flood; the Scottish school of scientists 

 maintained that it had all been accomplished by vol- 

 canic action. A violent feud ensued. Leopold Von 

 Buch asserted that both were right. He gave to 

 geology its present shape. I was then a student. 

 Being at the foot of the Jura, I saw rocks in places 

 where it was impossible for water to carry them. 

 The thought came to me that glaciers transported 

 rocks in Switzerland, and why not here also? I 

 thought: why might not glaciers occur in other coun- 

 tries than Switzerland? I went to other countries 

 and studied the evidence. I found that the rocks 

 which glaciers moved were polished, or rough and 

 scratched. Water rocks were hollowed in soft spots, 

 thus making prominent the hard places. Ice pro- 

 duces a smooth surface. Pebbles worn by water are 

 smooth like a hammered surface but dull, not 

 shiny; ice polishes the surfaces and scratches them. 

 If the ice goes in one direction all the creases will 

 run in one direction. Loose pebbles scratched by 

 ice and by water are also different. Erratic boulders 

 are always found in connection with loose materials 

 which are scratched and polished. Loose materials 

 are not stratified. I found out these facts in my 

 study in Germany, France, and in other countries. 

 I went to England, and there found evidence of this 

 glacial action. I was with a friend Mr. Buckland 

 and we were at first alone in our theory. 



"The conclusion we reached was, that at one time 

 the globe was much colder than it is at present. In 

 science one should never suggest anything for which 

 there is not some foundation. The glacial period 

 must have been posterior to the geological period 

 when mastodons and elephants inhabited the whole 

 globe and the climate was more tropical than it is 

 now. We estimated that ice was once 10,000 to 

 12,000 feet deep all over the globe. It is chiefly in 



