6i TOWN GEOLOGY. [H. 



dozen of them perhaps, which would do as well and 

 better than this. 



This is the temper which finds out truth, slowly, 

 but once and for all ; and I shall be glad, not sorry, 

 to see it in my readers. 



And I am bound to say that it has been by that 

 temper that this theory has been worked out, and the 

 existence of this past age of ice, or glacial epoch, has 

 been discovered, through many mistakes, many correc- 

 tions, and many changes of opinion about details, for 

 nearly forty years of hard work, by many men, in. 

 many lands. 



As a very humble student of this subject, I may 

 say that I have been looking these facts in the face 

 earnestly enough for more than twenty years, and that 

 I am about as certain that they can only be explained 

 by ice, as I am that my having got home by rail can- 

 only be explained by steam. 



But I think I know what startles you. It is the- 

 being asked to believe in such an enormous change in 

 climate, and in the height of the land above the sea* 

 Well it is very astonishing, appalling all but in- 

 credible, if we had not the facts to prove it. But of 

 the facts there can be no doubt. There can be no 

 doubt that the climate of this northern hemisphere 

 has changed enormously more than once. There can 

 be no doubt that the distribution of land and water,, 

 the shape and size of its continents and seas, have 

 changed again and again. There can be no doubt 

 that, for instance, long before the age of ice, the whole- 

 North of Europe was much warmer than it is now. 



Take Greenland, for instance. Disco Island lies in 

 Baffin's Bay, off the west coast of Greenland, in lati- 



