THE PROGRESS OF SCIENCE 



485 



sible for me to regard the earth as 

 free from rotation, if I conceive of 

 the centrifugal force, which acts on 

 all bodies at rest relatively to the 

 earth, as being a "real" field of gravi- 

 tation, or part of such a field? If 

 this idea can be carried out, then we 

 shall have proved in very truth the 

 identity of gravitation and inertia. 

 For the same property which is re- 

 garded as inertia from the point of 

 view of a system not taking part in 

 the rotation can be interpreted as 

 gravitation when considered with re- 

 spect to a system that shares the ro- 

 tation. According to Newton, this 

 interpretation is impossible, because 

 by Newton's law the centrifugal field 

 can not be regarded as being produced 

 by matter, and because in Newton's 

 theory there is no place for a "real" 

 field of the "Koriolis-field" type. But 

 perhaps Newton's law of field could 

 be replaced by another that fits in 

 with the field which holds with re- 

 spect to a "rotating" system of co- 

 ordinates? My conviction of the 

 identity of inertial and gravitational 

 mass aroused within me the feeling 

 of absolute confidence in the correct- 

 ness of this interpretation. In this 

 connection I gained encouragement 

 from the following idea. We are 

 familiar with the "apparent" fields 

 which are valid relatively to systems 

 of coordinates possessing arbitrary 

 motion with respect to an inertial 

 system. With the aid of these special 

 fields, we should be able to study the 

 law which is satisfied in general by 

 gravitational fields. 



A NEWS SERVICE FOR 

 SCIENCE 



Science Service is the name of an 

 agency newly established in Wash- 

 ington for the diffusion of knowl- 

 edge. It is generously supported by 

 Mr. E. W. Scripps and will be a cor- 

 poration conducted without profit, 

 all receipts being used for the work 

 and its extension. 



The Service will pay adequately for 

 notes and articles that are scientifi- 

 cally correct and of popular interest 

 and will dispose of them through the 

 existing news syndicates and in other 

 ways that will provide the largest pos- 

 sible circulation. It plans also to take 

 up motion pictures and all other 

 methods useful for the populariza- 

 tion of science. 



The first board of trustees of Sci- 

 ence Service is composed as follows : 

 Representatives of the National 

 Academy of Sciences 



Dr. A. A. Noyes, director, chemi- 

 cal research, California Institute of 

 Technology. 



Dr. R. A. Milikan, professor of 

 physics, University of Chicago. 



Dr. John C. Merriam, president, 

 Carnegie Institution of Washington. 



Representatives of the American As- 

 sociation for the Advancement of 

 Science 



Dr. D. T. MacDougal, director, 

 Desert Laboratory of the Carnegie 

 Institution. 



Dr. J. McKeen Cattell, editor, Sci- 

 ence and Scientific Monthly. 



Dr. George I. Moore, director, Mis- 

 souri Botanical Gardens. 



Representatives of The National Re- 

 search Council 



Dr. Vernon Kellogg, permanent 

 secretary, National Research Council. 



Dr. George E. Hale, director, 

 Mount Wilson Observatory of the 

 Carnegie Institution. 



Dr. R. M. Yerkes, chairman, Re- 

 search Information Service, National 

 Research Council. 



Representatives of the Scripps Estatc 

 Mr. E. W. Scripps, Miramar, Cali- 

 fornia. 



Mr. R. P. Scripps, Cleveland, Ohio. 

 Dr. W. E. Ritter, director, Scripps 

 Institution for Biological Research of 

 the University of California. 



Representatives of the Journalistic 

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Edwin F. Gay, president, New York 

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 City. 



Chester H. Rowell, former editor, 

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 California. 



William Allen White, editor, The 

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Dr. W. E. Ritter is president of 

 the board, Mr. R. P. Scripps, treas- 

 urer, and Dr. Vernon Kellogg, vice- 

 president and chairman of the execu- 

 tive committee This committee is 



