Sixth Year. 

 Vol. XI. No. 279. 



NEW YORK, June 8, li 



Single Copies, Ten Cents. 

 ^3.50 Per Year, in Advance. 



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



Editorial ...... 267 



The Discussion of the New York School System. • — Andrew D. 

 White's Proposed American University. — Washington Sci- 

 entific Societies. — Spontaneous Products of the Pupils of 

 Washington Schools. — National Museum. 



The Weather-Predictions . . . 267 



The Polytechnic Institute . . . 269 



Scientific News in Washington. 



Indian Jugglery . . . . . . 269 



The Unusual Prevalence of Fog during May . . 270 



Mental Science. 



Illustration of the Play Instinct .... 270 

 Hcad-Grouth in Cambridge Students . . . 271 



An Interesting Memory-Test .... 271 



Health Matters. 



Sea->icl-;ness ...... 272 



Function of the Hile ..... 272 



A New Ihpnotic ..... 272 



Smokers Vert'go ..... 272 



-A Leper Invasion of the United States . . . 272 



Race and Insanity ..... 272 



Electrical Science. 



Alternating Curient Electro-Motors . . . 273 



Electrical Welding ..... 



Difference of Potential between Metals in Solutions of Differ- 

 ent Strengths ..... 

 Expansion Galvanometer .... 

 The Water-Jet Telephone-Transmitter 



Book-Reviews. 



Missouri a Bone of Contention 



Popular Physics .... 



Our Native Ferns and Their Allies 



The Fundamental Principles of Chemistry . 



A Companion to School Classics 



Chronological Tables 



Physical and Industrial Training of Criminals 



Negro Myths from the Georgia Coast 



Lessons in Geometry for the Use of Beginners 



Trigonometry for Beginners 



Geometry in Space 



Notes and News 

 Letters to the Editor. 



Genealogy of Ideas . . . 0. T. Mason 



New York Schools Theodore F. Seward ; A Professional 



Obserz'er ...... 



Answers ...... 



273 

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 273 



274 

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 274 

 274 

 275 

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276 

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276 



27S 



278 

 278 



The Science Company, Publishei's, /^.y Lafayette Place, New Yoi^k. 



London assent: G. E. Stechert, 26 Kincr William Si., Strand. 



BRADLEY'S ATLAS OF^gE WORLD. 



A Complete American and Foreign Atlas, with isome{^^4^''^4:^r4ex to maps. Folio 



112. Maps and Plans. 



Wm. M. Bradley & Bro., 1026 Arch St., Phila., Pa. 



From Rev. James McCosh, D.D., LL.D., 



President of Princeton College. 

 It is very full and comprehensive, and is more minute in giving the 

 names and localities of places in all countries than any atlas I have seen. 

 It should be in all our libraries and in our large oihces. 



From William Libbey, Jr., 



Prof. Physical Geography in Princeton College. 

 It gives me pleasure to add my testimony to the value of Bradley's 

 Atlas, the first American work of the sort worthy of the name. I have 

 examined it closely and find it excellent in every way. The informa- 

 tion it contains is drawn from thelalest and best authorities, making it 

 easily the most reliable as it is the most recent work in its department 

 in existence. It will lake the lead among Geographical Atlases. 



From J. M. Buckley, D.D., 



Editor of Christian Advocate. 

 This Atlas approaches and may be said to attain, up to the present 

 date, the id^l of an atlas. We have perused it with reference to the 

 recent exploring expeditions sent to the Polar .Seas, Mexico, and Rus- 

 sia ; and the maps of Switzerland. Norway and Sweden, and the Dark 

 Continent, and have placed it in the editorial library as something 

 greatly to be desired and likely to be frequently consulted. 



From Prof. Geo. H. Cook, 



State Geologist. 

 The best work of the kind that I know of. It is up to |the times in 

 its matter and its maps are admirably prepared. I heartily commend it. 



From John H. Vincent, D.D. 



I have examined and subscribed for the mammoth volume of maps 

 published by Wm. M Bradley & Bro. It is a treasure bouse of infor- 

 mation. Geographical. Historical, and Statistical. I heartily commend 

 it to persons " who want the best." 



From the late General Wm. B. Hazen, 



Chief Signal Officer, Washington, D.C. 

 Your Atlas is just what is needed at home and abroad. 



From Gen. Fitz John Porter. 



The volume is very valuable. I have not seen a better set of maps. 



From Ellis A. Apgar. 



Late St.^te Supt. of Public Instruction. 

 I have examined Bradley's Atlas of the World, and it affords me 

 pleasure to say that it is the best published in this country. 



And a large list of prominent educators, including Jas. H. Mason Kno.x, D.D., President of Lafayette College ; Prof. B. 

 Youngman, of Lafayette College ; Rev. Noah Porter, D.D., LL D., President of Yale College ; Edw. H. Magill, .A.M., 

 President of Swarthmore College ; Wm. W. Patten, D.D., LL.D., President of Howard University ; Merville Edwards 

 Gates, Ph.D., LL D., President of Rutgers College ; W. I. Curtis, Principal of Hillhouse High School, New Haven, Conn.; 

 M. A. Newell, Principal State Normal School, Baltimore, Md. ; Edw. S. Ellis, Superintendent of Public Schools, Trenton 

 N. J., &c.,&c. 



