The Popular Science Monthly 



ISntered in the Post Office in Lancaster, Pa., as second-class matter. 



CONTENTS OF MARCH NUMBER 



Aerial Navigation. O. Chanitte. 



The Metric System: Shall it be Compulsory? Pro- 

 fessor W. Le Oonte Stevens. 



The Conservation of Energy in Those of Advancing 

 Years. Dr. J. Madison Taylor. 



The Royal Prussian Academy of Science, Berlin. 

 Edward F. Williams. 



The Tropical Station of Cinchona, Jamaica. Dr. N. 

 L. Britton. 



Education and Industry. Professor Enw. D Jones. 



Evolution Not the Origin of Species. O. F. Cook. 



Some Historical Aspects of Vegetarianism. Pro- 

 fessor Lafayette B. Mendel. 



Tokyo Teikoka Dragaku (The Imperial University 

 of Tokyo). Naciiidk Yatsu. 



The Progress of Science: 



Immanuel Kant ; Recent Progress in the Stmiy 

 of Radio-activity ; New Buildings for the Depart- 

 ment of Agriculture in Washington. Scientific 

 Items. 



CONTENTS OF APRIL NUMBER 



Recent Discoveries in Radiation and their Signifi- 

 cance. Professor R. A. Millikan. 



Evolution of the Human Form. Charles Morris. 



The Areqnipa Station of the Harvard Observatory. 

 Frofessor Solon I. Bailey. 



The Royal Prussian Academy of Science and the 

 Fine Arts, Berlin. Edward F. Williams. 



The Influence of Liebig on the Development ol 

 Chemical Industries. Dr. Carl Duisberg. 



The* Conservation of Energy in those of Advancing 

 Years. Dr. Madison J. Taylor. 



The Caucasian in Brazil. Thomas C. Dawson. 



The Air of the Luray Caverns. Dr. Guy L. Hunner. 



The Progress of Science : 



The Centenary of the Death of Priestley ; Pro- 

 fessor Eduard Zeller; Charles Emerson Beecher; 

 Science at Colorado College ; The Size of Families 

 ol College Graduates; The Study of the Sciences 

 and of Latin in the Secondary Schools. 



Index to Volume LXIV. 



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