SCIENCE 



Friday, March 4, 1921 



CONTENTS 



The American Association for the Advance- 

 ment of Science: — 



The Structural Failure of tlie Lithosphere: 

 Be. C. K. Leith 195 



fie Events: — 

 Dinner in Sonor of the Eetiring Secretary 

 of Agricultti/re ; The Annual Congress on 

 Medical Education; The Manufacture of 

 Chemicals for Research Work; Institute for 

 Food Research at Stanford University .... 207 



Scientific Notes and News 210 



University and Educational News 211 



Discussion and Correspondence: — 

 Human Nature as a repeating Factor — that 

 Thrice-told Tale: De. W. W. Campbell. 

 Galileo and Wood: Peofessoe Aethue 

 GoEDON Webstee. Archcological Specimens 

 for Museums: De. W. K. Moorehead. Pub- 

 lications of the Vienna Museum,: De. Dayid 



, Jordan 211 



Tlie Protection of British Optical Industries. 215 



Scientific BooTcs: — 

 Kraus and Hunt's Mineralogy: De. Ebgar 

 T. "Wheeey 215 



Special Articles: — 

 Add Production hy a New Sulfur Oxidizing 

 Bacterium: De. Selman A. Waksman", 

 Jacob S. Jofpe 216 



The American Chemical Society: Db. Charles 

 L. Paesons 217 



MSS. intended for publication and books, etc., intended for 

 review sbould be sent to The Editor of Science, Garrison-on- 

 HudBon, N. Y. 



THE STRUCTURAL FAILURE OF THE 

 LITHOSPHEREi 



As a foimdation for ordinary human activi- 

 ties it is but natural that the lithosnhere or 

 .solid earth should be a popular symbol of 

 strength and permanence; but the geologist 

 sees abimdant evidences that it has fared 

 badly in the contest with environmental 

 forces, past and present. It has been weak 

 and incompetent; it has bent, crumpled, 

 broken and mashed; structurally it has failed; 

 in considerable part it now consists of struc- 

 tural ruins. 



The problem of the structural geologist in- 

 cludes the restoration of these ruins and a 

 determination of the conditions and causes of 

 failure. His problem is not rendered easier by 

 the fact that it is seldom possible to see the 

 structures in three dimensions, and that he 

 must base his restoration on fragments of 

 evidence seen at the surface or on the very 

 limited outlook of undergroimd openings or 

 on inferences from environmental conditions. 

 Furthermore, the geologist seldom sees rock 

 failure in actual progress. If he does he may 

 not recognize it because the movement is so 

 slow. He arrives after the disturbance is over 

 and must infer the nature of the forces and 

 processes from the residts. In attempting to 

 picture conditions in the inaccessible deep 

 zones, he must make long range inferences 

 from the few available facts. 



The study of structural geology naturally 

 begins with the mapping and description of 

 separate structures like folds, faults, joints, 

 and cleavage. Too often this has been re- 

 garded as the end and not as a step toward the 

 understanding of the structural conditions as a 



1 Address of the retiring vice-president and 

 chairman of Section E, the American Association 

 for Advancement of Science, Chicago, December 

 28, 1920. 



