EXAMPLES OF TEACHING METHODS 355 



or whether it is the product of secondary enrichment; whether, in other 

 words, it may continue far down in the earth or whether it will change 

 in character a relatively short distance below the surface. Two ores, 

 chalcocite and argentite, are of extreme interest in this respect and both 

 have from time to time called for interpretation. 



Dr. Berkey has thus developed a branch of work called "Problems in 

 applied petrography," and has now no less than 150 actual cases which 

 he may pass out to his students with the same data and in exactly the 

 same form as they have come to him or to me or to a few of our friends 

 in the field. After a student has studied, thought over, and interpreted 

 his case, his results are often discussed for the benefit of the others in the 

 class, and are then checked up by the work of older observers on the 

 same material. The interest aroused in young, vigorous, and inquiring 

 minds is impressive and the line of attack has proved to be one of excep- 

 tionally stimulating character. A successful teacher, indeed, must have 

 not only an inquiring and investigating mind himself, but if he main- 

 tains good and inspiring relations with his students, he must make them 

 sharers in his work and experiences. This relation is the one with which 

 to follow up fundamental instruction if we are to train investigators. 



Importance of full personal Eeferences to the Work of 

 PROMINENT Geologists 



There is one other side which I believe to be also very important. A 

 teacher should speak often, freely, and appreciatively of the men who 

 have done the geological work in the past and who are doing it today. 

 The personal appeal of actual service well performed is very strong, and 

 when a subject, such, for instance, as the inspiring theme of Lake Su- 

 perior geology, is discussed with an advanced class, it is well to tell the 

 young people of the men who deciphered it; when and how they came 

 into the field, and what they each accomplished. It was rough work. 

 There was often thick brush; there were old lumber jobs burned over; 

 second growth almost impenetrable; swamps, black flies, gnats, and 

 mosquitoes. 



Xot every one knows, as I learned once when talking with our lamented 

 fellow-member. President Van Hise, that after his first summer's work 

 he swung himself on the train for home and said to himself, "Thank 

 Heaven, I never will have to go back into that country again." Hard- 

 ships seem easier if the beginner knows that he is only the last member 

 added to a long and honorable procession. Books such as "Shaler's auto- 

 biography" ; the "Life and letters of Josiah Dwight Whitney" ; "Life and 

 XXV — Bull. Geol. Soc. Am., Vol. 31, 1910 



