Established in i8'/2. 



THE POPULAR SCIENCE 



MONTHLY 



3 DOLLARS 25 CENTS 



A YEAR A NUMBER 



Edited by 



Professor J. McKeen Cattell 



THE POPULAR SCIENCE MONTHLY for June opens \\\W\ an article by Prof. 

 J. W. Tuomey, of the newly established Yale Forest School, on the forest reservations 

 of the United States. The importance of these great reservations for the future of the 

 country is scarcely appreciated, and this article, with its beautiful illustrations, will 

 call attention to the.se national parks, whose area is more than fifteen times the State 

 of Connecticut. Another elaborately illustrated article in the number is one b}^ 

 Professor Francis H. Herrick, of Adelbert College, describing his newly discovered 

 method of photographing and studying birds at arm's length. Dr. David Starr 

 Jordan, President of Stanford University, contributes a study of the decay of races 

 through the survival of the unfit, arguing that war weakens the nation by destroying 

 its best material. Professor Robert H. Thurston, Director of Sibley College, Cornell 

 University, traces the progress and tendency of mechanical engineering during the 

 nineteenth century. Professor James Lewis Howe, of Washington and Lee Universit}^ 

 contributes an article on the periodic law, a scientific generalization, the importance of 

 whcih is ranked with the law of gravitation or the theory of evolution, yet regarding 

 which many intelligent people are not informed. Mr. Havelock Ellis continues his 

 study of British men of genius, tracing their marriage and .family and the age to 

 which they lived. An address by the late Professor Henry A. Rowland, of the Johns 

 Hopkins University, entitled "A Plea for Pure Science," points out the defects and 

 needs of science in America. Dr. Gary N. Calkins, of Columbia University, describes 

 the malaria-bearing parasite by means of which the mosquito spreads this disease, the 

 most important scientific advance since the discovery of the Rontgen Rays. The 

 number, as usual, closes with short notes describing the most recent progress of 

 science. 



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