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A WEEKLY NEWSPAPER OF ALL THE ARTS ANT) SCIENCES 



PUBLISHED BY N. D. C. HODGES, 874 BROADWAY, NEW YORK. 



Tenth Yeak. 

 Vol. XIX. No. 



APRIL 29, 1892. 



Single Copies, Ten Cents. 

 $3.50 Per Year, in Advance. 



Contents. 



New Method of Protecting Buildings 



FROM Lightning N. D. C. Hodges. 339 



Collecting Gorilla Brains. E. H. 



Nassau 340 



Notes and News 341 



The Detection of Artificial (Imita- 

 tion) Gems. W. G. Miller 344 



The Systematic Position of the Diptera. 



J. M. Aldrich 344 



Deblooming Mineral Oils. D. T. Mar- 

 shall 245 



Astronomical Notes. Edited by George 



A. Hill 246 



Mr. Petrie's Discoveries at Tel-el- 



Amarna. S. Y. Stevenson 246 



The Rolling of Ships 247 



Letters to the Editor. 



A Fire Ball. C. C. Bayley 349 



Lightning. Marshall Henshaw .... 249 

 Periodicity of the Aurora. M. A. 

 Veeder 250 



Among the Publishers 251 



Entered at the Post-Offlee of New York, N.Y., as 

 Second-Class Mail Matter. 



Travels Among the Great Andes of the Equator. 



By Edward Whymper. With Maps and 150 Illusti-ations by various arfcists, and 

 engraved by the author. Large 8vo, handsomely bound, gilt top, uncut edges, 

 §6.00. 



" A memorable addition to the literature of travel. Much, of what Stanley has done for an 

 unknown region of the earth's lower surface, Mr. Whymper has done for remote and comparatively 

 unknown regions of the earth's most interesting and lofty altitudes."— iV. Y, Times. 



"It is abook of infinite interest. 

 It is fascinating." — Cincinnati 

 Com. Gazette. 



" By all odds the finest book of 

 its kind issued in some years 

 ipast. '^—Fhiladelphia Telegraph. 



" The book is exhaustive and 

 deeply interesting."- ^osiOJi Ad- 

 vertiser. 



"One of the most really valu- 

 able books of the year." — Albany 

 Journal. 



"The work is of spatial value 

 as a scientific record, and the ac- 

 count of the journey is most en- 

 tertaining." — Science. 



" The volume is one of the most 

 interesting descriptions ever 

 written." — Cleveland Leader. 



''^ Sold by all booksellers, or sent, postpaid, by 



CHARLES SCRIBNER'S SONS, 743-745 Broadway, Sew York. 



THE POPULAR SCIENCE MONTHLY. 



A culture that lacks science is a one-sided culture. 



The Popular Science Monthly is the one periodical that gives access to the scientific culture of the time, and it will in the future 

 represent scientific thought and achievement even more fully than it has in the past. The valuable series of illustrated articles on 



THE DEVELOPMENT OF AMERICAN INDUSTRIES SINCE COLUMBUS, 



now running in the Monthly, will be continued. There have already been published three articles on The Woolen Manufacture, by 

 S. N. D. North; four articles on The Making of Iron and two on The Making of Steel, by W. F. DuRFBE. The first of two articles 

 on American Pottery appears in the December number. All of these are profusely illustrated ; and similar papers on The Cotton 

 Manufacture, by Edward Atkinson and Gen. W. F. Draper; Piano-Making, by Daniel Spillane ; Glass-Making, by Prof. C. Han- 

 ford Henderson ; and on The Leather, Silk, Paper, Agricultural Machinery, and Ship-building Industries will appear in course. 



Hon. Carroll D. Weight will continue his incisive Lessons from the Census. Dr. Andrew D. White will contribute some con- 

 cluding papers on The Warfare of Science, and there will be occasional articles from Hon. David A. Wells and from David Starr 

 Jordan, President of Stanford University. 



The other contents of the coming numbers can not be definitely announced at this time, but the character of the contributions may 

 be inferred from 



SOME OF THE ARTICLES OF THE PAST YEAR. 



The Stokage of Electricity (illustrated). Prof. Samuel Sheldon. 



The Decline of Rural New England, Prof. A. N. Currier. 



Cultivation op ^6Al in the Bahamas (illustrated), J. I. Northrop, Ph. D. 



KocH"s Method oP Treating Consumption, G. A. Heron, U. D. 



Street-Cleaning in Large Cities, Gen. Emmons Clark. 



Professor Huxley on the War-Path, The Duke of Argyll. 



Sketch of Daniel C Brinton (with Portrait), C C. Abbott. 



Some Games of the ZuSi (illustrated), John O. Owens. 



Our Agricultural Experiment Stations, Prof. C. L. Parsons. 



The Colors of Letters, President David Starr Jordan. 

 Dress and Adornment (illustrated), Prof. Frederick Starr. Four articles. 

 Professor Huxley and thk Swine Miracle, W. E. Gladstone. 

 Illustrations op Mr. Gladstone's Controversial Method, Prof, T. I 



Hiucley. 

 The Doctrine of Evolution, John Eiske. 

 Limits of State Duties, Herbert Spencer. 

 University Extension, Prof. C. Eanford Henderson. 

 Some of the Possibilities op Economic Botany, Prof. G. L. Ooodale. 



Twenty years ago our first number was issued with the following statement : ' ' The Popular Science Monthly has been started to help 

 on the work of sound public education, by supplying instructive articles on the leading subjects of scientific inquiry. It will contain papers, 

 original and selected, on a wide range of subjects, from the ablest scientific men of different countries, explaining their views to non- 

 scientific people." This task has grown larger and more important with the continual growth of science, and the scope and resources of 

 the Monthly have been correspondingly widened. No pains will be spared for its adequate performance in the future. 



EDITED BY WILLIAM JAY YOUMANS. 



$5.00 a year; 50 cents a number. 



D. APPLETON & CO., Publishers, 1, 3, and 5 Bond Street, New York. 



