Preface vii 



deemed that a useful task might still be undertaken if 

 the story of a few of the great pioneers were briefly 

 narrated, and if from their struggles, their failures and 

 their successes, it could be indicated how geological ideas 

 and theories gradually took shape. Such was the origin 

 and aim of the following lectures. 



The personal intercourse to which, after an absence 

 of eighteen years, I looked forward with vivid interest 

 proved to be a source of the keenest enjoyment. Eenew- 

 ing old friendships with some of the veterans of the 

 science, and forming fresh ties of sympathy with many 

 younger workers who have come to the front in more 

 recent years, I could not but be impressed by the extra- 

 ordinary vitality which geology has now attained in the 

 United States. Every department of the science has its 

 enthusiastic votaries. Surveys, professorships, museums, 

 societies, journals in almost every State are the outward 

 embodiment of the geological zeal that appears to animate 

 the whole community. This remarkably rapid develop- 

 ment of the science has not arisen from any influence 

 derived from without, but springs, as it seems to me, from 

 the marvellous geological riches of the American continent 

 itself. In minerals and rocks, in stratigraphical fulness, 

 in palaeontological profusion, in physiographical illustra- 

 tions, the United States have not only no need to borrow 

 from Europe, but in many important respects can produce 

 examples and materials such as cannot be equalled on 

 this side of the Atlantic. Had the study of the earth 



