fTORTH WHILE BOOKS 



METEORS BY CHARLES P. OLIVIER, PH.D. 



"This is a timely book," says the Journal of the Franklin 

 Institute; "it is the first general treatment of meteoric 

 astronomy since 1871 .... The story is completely 

 and succinctly told in an inviting and charming manner. 

 The arrangement permits one to read the non-technical part 

 of the book and omit, without a sense of incompleteness, the 

 well told chapters that contain the mathematical treatment 

 . . . . The author has perhaps contributed more to 

 meteoric astronomy than any other living American." 6x9. 

 Striking cover design. $6.00. 



DICTIONARY OF BOTANICAL EQUIVALENTS 



By ERNST ARTSCHWAGER AND EDWINA M. SMILEY 

 The second edition, revised and enlarged. Now includes 

 French-English, German-English, Dutch-English, Italian-Eng- 

 lish. Designed for every student and investigator who reads 

 foreign botanical literature. A practical reference volume. 

 Blank pages at the end of each section for addenda. Price 

 $3.25. 



TREE ANCESTORS By EDWARD WILBER BERRY, PH.D. 



This is a glimpse into the past of our familiar tree stocks. 

 "The reader need not be a botanist nor a biologist to appre- 

 ciate this treatise," says the Mercury, "but after reading it, 

 he will be a better student and a more enthusiastic disciple 

 of Nature." 6x9. 270 pages. Forty-eight illustrations. 

 Price $3.00. 



WEATHER PROVERBS AND PARADOXES 



By WILLIAM J. HUMPHREYS, PH.D. 



"This handbook on weather proverbs and paradoxes by 

 one of the foremost experts on meteorology is invaluable 

 and should be on the library table of every well-read scholar," 

 says Science and Invention. "Get it. Study it and you'll 

 discover an appreciation of Nature in her 'visible forms' that 

 you have never felt before," is the comment of the Mercury. 

 Illustrated. Price $1.50. 



THE WILLIAMS & WILKINS COMPANY 



Publishers of Scientific Books and Periodicals 

 BALTIMORE, U. S. A. 



