t)4 PROCEEDINGS OF THE AMHERST MEETING 



8. K. H. Johnson offers a suggestion for the construction of structural 

 models which deserves careful consideration. He says : 



"Valuable models can be made from sheet lead mounted in a frame. This 

 lead can readily be bent to illustrate structure and it can be painted later to 

 bring out the geologic lines." 



He made a structural map of the entire United States in this way. He 

 states that such models can not well he made by a dealer, hut that each 

 teacher can, with patience and skill, construct his own models. 



9. The Director of the United States Geological Survey Avrites that — 



"A great deal of apparatus has been designed and used by members of the 

 Geological Survey for studying various geologic phenomena, and some of it 

 could doubtless be adapted for the use of schools. Among apparatus of this 

 sort may be mentioned the compression machine used by Bailey Willis in his 

 experiments on Appalachian structures ; apparatus devised by Wentworth for 

 the study of certain problems connected with sedimentary rocks ; apparatus 

 devised and used by Gilbert in his studies of debris transportation; Van Os- 

 trand's apparatus for the study of the diffusion of solids ; Melcher's apparatus 

 for the study of the porosity and diffusion of oil and water through rocks, etc. 

 None of this apparatus is for sale and much of it is too complex for general 

 school use, but modifications might be made, so that the result would be sim- 

 ple, rather inexpensive, and adaptable for teaching." 



Each teacher must decide for himself whether or not any of this ap- 

 paratus can be used advantageously, but it seems probable that it will be 

 found more useful in research courses than in elementary courses in 

 geology. . 



10. Director H. Foster Bain, 6 of the Bureau of Mines, states that — 



"The Mills' experimental apparatus for studying the migration, accumulation, 

 and recovery of petroleum and natural gas would be useful for the elementary 

 class-room and laboratory and for investigational work by advanced students, 

 as it would give the student the clearest possible understanding of the rela- 

 tions that structure, bedding, textures of sand, and other uuderground condi- 

 tions bear to the migration, accumulation, and recovery of oil and gas. It 

 might also be used for a model, or permanent exhibit." 



Persons wishing to construct such apparatus should write to Mr. Mills. 

 A model such as this would be of real value in elementary teaching. 



11. Prof. W. M. Davis years ago constructed a working model illus- 

 trating his view of the faulting of the Triassic rocks of the Connecticut 

 Valley, which, if so modified as to be less cumbersome, would be helpful 

 in teaching faulting in general geology. In its present form it will prob- 

 ably not have a wider use than in the past. It is hoped that some in- 



8 Economic Geology, vol. 13, p. 398; vol. 16. p. 124. 



