SCIEN 



^i'^^ 





LEntered at the Poat-Offlee of New York, N.Y., as Second-Class Matter.j 



Ninth Year. 

 Vol. XVIII. No. 441. 



NEW YORK, July 17, 1891. 



SiNQi-E. Copies, Ten Cents. 

 $3.50 Per Year, in Advance. 



NenB Method of Protecting Property 

 from Lightning. 



The Lightning Dispeller. 



The Patent LightninK Dispeller is a conduc- 

 tor specially designed to dissipate the energy 

 of a lightning discharge, — to prevent its 

 doing harm, — placing something in its path 

 upon which its capacity for causing damage 

 may be expended. 



No recorded case of lightning stroke has 

 yet been cited against the principle of the 

 Dispeller. So far as known, the dissipation 

 of a conductor has invariably protected under 

 the conditions employed. 



Correspondence solicited. 



AGENTS WANTED. 



N. D. C. HODGES, 



47 Lafayette Place, - • - New York. 



MIMEDAIC fABiNET Specimens. Collections. 

 iriinLllnLui For Hlowpipe Analysis. 



Lart^est and fioest stock in U. S. 100pp. Illustrated 

 CatalotiUP paper bound, 15c ; clotb bound, 25o. 

 ^KO. L. ENGLISH & CO, Mineralogists, 

 Removed to 733 & 735 Broadway, New York. 



Course of Mineralogy for Yonng People. 



Third Grade ready. contaiDing directions how to 

 studv minerals by means of blowpipe analysis. 



Book. Collection, drrespondence one dollar 

 postage, 25 cents. Address 



GUSTAVE GUTTENBERG, 

 Central High School, Pittsburgh. Pa 



ROSE POLYTECHNIC INSTITUTE. 



TKllUE HALTt, Ii\UI.\M.— .V SI.1H10L OK KSGISFLltiAU. 



Well endowed, veil equipped depiirtments of Civil, 

 Mechanical and Electrical Entriueering, Chemietn, 



WALKER PRIZES IN NATURAL HISTORY. 



The Boston Society of Natural History 



offers a first prize of from $60 to $100, and a seond 

 prize of a sum not exoeedine S50, for the b^-st me- 

 moirs, in English, on one of the followiog subjects: 



1. An orip;iual investigation into any of the prob- 

 lems connecte'i with the geology oi the last ic-'j epoch 

 in New England; any of the glacial features, as. for 

 instance, the distribution and history of morainal 

 deposits and eskers, or of sand plains may be se- 

 lected. 



2. An original investigation into the recent changes 

 of level of the whole or of a part of the shore line of 

 the eastern United States. This inquiry must in- 

 clude observations on and discussinns of the phe- 

 nomena exhibited by elevated sea margins and sub- 

 merged forests. 



3 A study of any river valley in New England 

 containing an area of not less than one hundred 

 square miles; the inquiry to include the pre^lacial 

 history of the stream, the changes effected in the 

 basin by the last ice epoch, the relation of the valley 

 to the neighboring basins, and to changes of level of 

 the sea. 



Each memoir must be accompanied by a sealed 

 envelope, enclosing the author s name and super 

 scribed by a motto corresponding to one borne by 

 the manuscript, and must be handed to the Secre- 

 tary on or before April 1st, lfr92. 



Prizes wi'l not be awarded unless the memoirs are 

 deemed of adequate merit. 



For further particulars apply to 



SAMUEL DEXTER, Secretary. 



Boston. July 1. 1891. 



AN 



A!VIERICAN 

 RAILWAY 



GEOLOGICAL 

 GUIDE. 



Giviug the Geological Formation along the 

 Railroads, with A Ititude above Tide- water, 

 Notes on Interesting Places on the Eoutes, 

 and a Description of each of tne Forma 

 tions. By James Macfarlane, Ph.D., 

 and more than Seventy five Geologists. 

 Second edition, 1890. 426 pages, 8vo. 

 Cloth, $3.50. 



D. APPLETON&OO., Publishers.New York. 



PROTECTION FROM LIGHTNING. 



All the capital desired for the parent com- 

 pany to handle my patents on a new method 

 of protecting buildings from lightning has been 

 subscribed. Sub-companies and agencies to 

 introduce the invention are forming, and any 

 desirous of taking State-rights may address me, 

 for the present, as below. 



The English patent is for sale. 



N. D. C. HODGES, 47 Lafayette Place, New York. 



QUERY. 



Can any reader of Science cite 

 a case of lightning stroke in 

 which the dissipation of a small 

 conductor (one sixteenth of an 

 inch in diameter, say,) has failed 

 to protect between two horizon- 

 tal planes passing through its 

 upper and lower ends respective- 

 ly? Plenty of cases have been 

 found which show that when the 

 conductor is dissipated the build- 

 ing is not injured to the extent 

 explained (for many of these see 

 volumes of Philosophical Trans- 

 actions at the time when light- 

 ning was attracting the attention 

 of the Royal Society), but not 

 an exception is yet known, al- 

 though this query has been pub- 

 lished far and wide among elec- 

 tricians. 



First inserted June 19. No response 

 to date. 



N. D. C. HODGES, 



47 LAFAYETTE PLACE, 

 NEW YORK. 



On Jan. 1st, and at intervals of two months 

 since, has been published the New Zealand 

 Journal of Science, dealing with all branches 

 of natural science, especially in relation to 

 the colony. Subscription (including postage 

 to America). 12s. 6rf per annum, payable to 

 the Editor, care Matthews, Baxter & Co., 

 DowlingSt., Dunedin, N. Z. 



