SCIENCE 



Sixth Year. 

 Vol. XI. No. 280. 



NEW YORK, June 15, li 



Single Copies, Ten Cents. 

 ^3.50 Per Year, in Advance. 



Entered at New York Post-Office as Second-Class Mail-Matter. 



Editorial 



Statistics of Farm-Labor. — The Contest in (he New York 

 Board of Education. — London Publishers and International 

 Copyright. — Weather Prognostications. 



The Crenitic Hypothesis and Mountain-Build- 

 ing . . . . . JV. S. Shaler 

 Scientific News in Washington. 



A Direction-Current Meter 

 Caliinets of Typical American Rock 

 Fine Specimens of Serpentine 

 Objibwa Pictographs in the West 

 Yellow-Fever in Florida 

 Intere^ti^g Phenomenon . 



Health Matters. 



Yellow-Fever 



279 



282 

 282 

 282 

 283 

 283 



2S3 



Electrical Science. 



Novel Current-Registering In-lrument 



The Short Series Electric Railway System . 



An Improvement in Secondary Batteries 



Influence of Temperature on the Magnetization of Iron 



The Mordey Alternating-Cuirent Dynamo . 



Incandescent Lamps in Explosive Gases 



Book-Reviews. 



A Texl-Book of Biology . 

 Ethics of Bo.xing and iWanly Sport . 

 Medicjl Nursing . 

 Bradley's Alias of the World 



Notes and News 

 Letters to the Editor. 



An Unusual Auroral Bow . 



The People and the Common Schools 



Reflex Speech 



Answers 



H. Helm Cliyton 



Edward H. Boyer 



C. Mains 



284 

 284 

 284 

 284 

 284 



284 



285 

 285 

 285 



286 



289 

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The Science Company, Publishers, ^y Lafayette Place, New York. 



London agent: G. E. Stechert, 26 Kinz William St., Strand. 



A NEW Bl 



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FIRST BOOK IN PHYSIOLOGY AND HYGIENE. By J. H. Kellogg, M.D., Member 

 of the American Medical Association, the American Public Health Association, Societe 

 D' Hygiene of France, British American Association for the Advancement of Science, Michigan 

 State Board of Health, etc. 



The design of this book is to present, in as simple a manner as possible, such hygienic and physiological facts as are 

 necessary to give to children a knowledge of the laws of healthful living. So far as possible technical terms have 

 been avoided, and no matter has been introduced which has not practical reference to the preservation of health. The 

 subject of Narcotics and Stimulants receives due attention, and is treated in such a manner as to adapt_ the book to 

 the requireiTients of recent laws relating to temperance in the public schools. The language, so far aspossible, is clear and 

 simple, and definitions and statements are i)resented in a style suited tO the Comprehension of children, and 

 calculated to arouse their interest in the subject studied. 



Price for e.xamination or introduction, 33 cents; list price, 40 cents. 



BOOKS IN NATURAl7 SCIENCE, 



SUITABLE FOR CLASS WORK AND SUPPLEMENTARY READING. 



Hooker's Child's Book of Nature, in three parts. 



Cooper's Animal Life in the Sea and on the Land. 

 Herrick's Chapters on Plant Life. 



Treat's Home Studies in Nature. 



Correspondence with reference to text-books is cordially invited, and will be carefully attended to. 



HARPER & BROTHERS, Pi^shers, Franklin Sqnare, R Y. 



WESTERN AGENCY, PHILADELPHIA AGENCY, NEW ENGLAND AGENCY, 



25s & 257 Wabash Avenue, Chicago, III. 1022 Arch Street, Philadelphia, Pa. 50 Bromfield Street, Boston, Mass. 



