Stai &y, 



Vol. LVIl. No. 5. . SEPTEMBER, 1900. 



THR *&•(*. 



POPULAR SCIENCE 

 MONTHLY. ijggk 



juulLliHArv 

 EDITED BY J. MchEEN CATTELL. Wg\ <**** 



CONTENTS : 



The Modern Occult. Professor Joseph Jastrow 449 



Birds as Flying Machines. Frederick A. Lucas 473 



Electric Automobiles. Wm. Baxter, Jr 479 



The Human Body as an Engine. Professor E. B. Rosa 491 



Chapters on the Stars. Professor Simon Newcomb, IT. S. N 500 



The Psychology of Red. Havelock Ellis 517 



The Expenditure of the Working Classes. Henry Hiogs 527 



The Conquest of the Tiopi cs Dr. George G. Groff 540 



Discussion and Correspondence : 



Poetry and Science : Pkofessok L. W. Smith. Antiquity of the Chewing 



Gum Habit : Dr. Robert E. C. Stearns 546 



Scientific Literature : 



A Grammar of Science ; The Teaching of Elementary Mathematics ; Geology ; 

 A Yearbook of Biology ; Astrophysics ; Experimental Medicine ; Ichthyology for 

 Anglers ; Microscopy of Drinking-water : o50 



The Progress of Science : 



Marine Biological Laboratories ; Woods Holl ; Cold Spring Harbor ; Research 

 Work and Courses of Instruction ; Summer Schools ; The Paris Exposition and 

 Its Congresses ; The Fayerweather Bequest ; The International Catalogue ; 

 Radio-active Substances ; Scientific Kite Flying ; Count Zeppelin's Air Ship ; 

 The P k ecent Eclipse ; Legislation Regarding the Importation of Animals 555 



MrCLURE, PHILLIPS & COMPANY, 



NEW YORK: 141 EAST J 5th STREET, 



london': 10 norfolk street, strand, \v . c. 

 Single Number, lT) Cextb. Yearly Subscription, $3.00. 



Copyright, 190u, by McCLl'RE, PHILLIPS & COMPANY. 

 Entered at the Post Office at New York, and admitted for transmission through the mails at second-class r&iea- 



