78 PROCEEDINGS OF THE AMHERST MEETING 



cates that when the publication describing these maps appears teachers of 

 geology and physiography will have a long-desired and useful addition 

 to their teaching equipment. 



Prof. A. C. Lane offers the following suggestion, which is worthy of 

 careful consideration: 



"I should welcome as a United States Geologic Survey bulletin a catalogue 

 raisonnee of their illustrations which one could bind with blank pages inter- 

 leaved, and which should be in the form of a dictionary of geologic terms with 

 references to good illustrations of the same. If a first edition of such a bulle- 

 tin could be issued and then all interested be invited to contribute to a second 

 edition in which published or unpublished material especially illustrating 

 words or ideas not well illustrated in the first should be included, it would be 

 very helpful. If there were objections to the United States publishing this, 

 the Geological Society of America might well publish the additional material 

 as a supplement at its own expense." 



Moving Pictures 



ANIMATED BLOCK DIAGRAMS OR CARTOOXS 



The most promising undeveloped field for teaching geology and physi- 

 ography, and possibly the best ever offered, is moving pictures of ani- 

 mated block diagrams or cartoons. The possibility of this means of 

 illustrating geology and physiography is far-reaching, and it is safe to 

 forecast that in the near future geologic and physiographic phenomena 

 which at present the average student fails to understand thoroughly will 

 be made clear. The difficulty will be to find a man to make these dia- 

 grams who possesses that rare combination — a keen mind, broad field 

 experience, artistic ability, and common sense. Prof. W. M. Davis, in 

 this country, could do it and perhaps two or three others. 



Some of the more obvious subjects are these : 



(1) Let animated block diagrams of a coast show the slow drowning 

 of the region ; then, on the cessation of the subsidence, let the waves cut 

 away the headlands and form stacks, caves, spouting horns, and other 

 characteristic forms and, in general, roughen the coast. Then, as the 

 coast is eroded and passes from youth through maturity to old age, let 

 I lie reel show the many features of interest and importance which result 

 from marine erosion and deposition, such as the formation of wave-cut 

 and wave-built terraces, bay-head beaches, spits, bars, tied islands, dove- 

 tailed sediments, littoral and shoal deposits, and other phenomena which 

 need elucidation. Let the animated cartoons next bring to the eve a 

 slowly rising coast, with the production of a coastal plain; let the eleva- 

 tion then (lose with the formation of barrier islands, such as that on 



