406 Scientific Intelligence. 



9. Wireless Telegraphy and Telephony Popularly Explained ; 

 by Walter W. Massie and Charles R. ITnderhill. Pp. 76. 

 New York, 1908 (D. Van Nostrand Co.). — This book is intended 

 to be a simple, elementary exposition of the inception and devel- 

 opment of wireless telegraphy and telephony. The space devoted 

 to the latter subject is less than four pages. There are a number 

 of simple diagrams and some excellent half-tone plates showing 

 elaborate apparatus. The book closes with a highly speculative 

 "interview" by Nikola Testa, in which a few of the wonders to 

 be wrought within the near future by the application of wireless 

 transmission are briefly outlined. b. b. b. 



10. An Introduction to the Science of Radio- activity ; by 

 Charles W. Raffety. Pp. xii, 208.. New York, 1909 (Long- 

 mans, Green & Co.).— The author has " endeavoured to give a 

 concise and popular account of the properties of the radio-active 

 elements and the theoretical conceptions which are introduced by 

 the study of radio-active phenomena. This work, as its title 

 indicates, does not claim to be more than an introduction to the 

 subject, and no attempt has been made at an exhaustive treat- 

 ment." The attempt appears to have been distinctly successful, 

 however, and the book is in many respects superior to others of 

 the same class which have previously appeared. The method 

 in which the subject is treated follows very closely along the 

 lines originally laid down in Rutherford's familiar treatise, and 

 is frequently suggestive of the author's familiarity with collected 

 works of this sort rather than with the original papers in the 

 literature. A notable and unfortunate exception is to be found 

 in the somewhat detailed discussion of the very questionable 

 results recently obtained by Ramsay in experiments with the 

 radium emanation. b. b. b. 



II. Geology and Natural History! 



1. Publications of the U. S. Geological Survey, George Otis 

 Smith, Director. — Recent publications of the IT. S. Geological 

 Survey are noted in the following list (continued from p. 86) : 



Topographic Atlas. — Thirty-seven sheets. 



Folios. — No. 160. Accident-Grantsville Folio, Maryland-Penn- 

 sylvania-West Virginia. Description of the Accident and 

 Grantsville Quadrangle ; by G. C. Martin. Prepared under the 

 supervision of William Bullock Clark, cooperating geologist. 

 Pp. 14, with 8 maps, columnar sections. 



No. 162. Philadelphia Folio. Norristown, Germantown, 

 Chester and Philadelphia Quadrangles, Pennsylvania-New 

 Jersey-Delaware ; by F. Bascom, W. B. Clark, N. H. Darton, 

 H. B. Kummel, R. D. Salisbury, B. L. Miller and G. N. 

 Knapp. Pp. 23 ; 2 topographic maps; 3 colored geologic maps; 

 columnar sections and 21 figures. 



