DEMONSTRATION MATERIAL IN GEOLOGY 77 



(1) A number of correspondents suggested that the Geological Society 

 of America appoint a committee to establish an office to which titles and 

 negatives could be sent, but the changing personnel of a Geological So- 

 ciety committee makes such a solution impractical; (2) others that the 

 proposed Federal Department of Education should establish a clearing- 

 house for lantern slides; (3) others that the Geologic Survey be urged 

 to take hold of the matter; and still others that the National Research 

 Council take this up as a part of its work. 



The Federal Survey has 80,000 photographs and a large staff of trained 

 geologists and geographers and could, without doubt, do this work better 

 than any other organization. Director George Otis Smith writes that the 

 Survey will be glad to cooperate in making more available the Survey 

 photographs, provided that it can be done without entailing considerable 

 additional expense. 



This is a matter which requires careful and immediate attention, and it 

 is hoped that one of the above solutions or some better one may be found. 



It is, perhaps, evident to all teachers of geology and physiography that 

 many of the lantern slides shown in class, especially if they are from 

 negatives taken by the teacher, are not as fine as the teacher thinks, be- 

 cause, having a mental picture of the scenery shown on a slide, he sees 

 on the screen much more than the student can. Without doubt, every 

 collection would be greatly improved if many of the slides were destroyed. 



The Geological Division of the National Eesearch Council, 1701 

 Massachusetts Avenue, Washington, D. C, has a complete file of the 

 catalogues of foreign dealers in lantern slides and will give the addresses 

 of such to correspondents. 



Topographic Maps 



Of the excellent material for the teaching of geology which the United 

 States Geological Survey has provided, none has been more* useful than 

 Professional Paper 60, entitled "The interpretation of topographic 

 maps." The first edition of this monograph has long since been ex- 

 hausted, and, unfortunately, long before many colleges and universities 

 had secured enough copies for class-room use; but a second edition has 

 recently appeared and is ready for distribution. 



A letter from the Director of the United States Geological Survey 

 states that geographic descriptions of a set of 100 of the more recent con- 

 tour maps that illustrate specific physiographic features "is contemplated 

 and is being undertaken by the Physiographic Committee" of the United 

 States Geological Survey. A preliminary circular which lists the various 

 physiographic features represented on the different maps of this set indi- 



