SCIENC 



New Series. 

 Vol. XI. No. 279. 



Friday, May 4, 1900. 



Single Copies, 15 cts. 

 Annual Subscription, 85.00 



MINIATURE IITCAITDESCENT LAMPS. 

 MINIATURE LAMP RECEPTACLES. 

 X-RAY TUBES AND APPARATUS. 

 FLUOROSCOPES. — . 



Catalogues on Applfcation. 



Edison Decorative and Miniatore Lamp Department, 



(Geheral Electric Company), 



HARRISON, N. J. 



~WM. GAERTNER & CO. 



Astronomical and Physical Apparatus 



152-158 EAST 56th ST., CHICAGO 



SPEOIALTIES 



Standard Apparatus of New and Improved Designs 

 READING Microscopes and telescopes 

 Astronomical telescopes Heliostats 



Spectroscopes Dividing Engines, Comparators 



Michelson Interferometers General Laboratory Apparatus 



Bolometers Universal Laboratory Supports 



MINERALS. 



Having just receiTed a large shipment of European and Mexican 

 minerals, we now offer Bismuth, Amethyst, Strontianite, 

 Niccolite, Sylvanite, Allemontite, Scheelite, Native 

 "~~^"^^^^^^~~^~"^-^~~— ~"^^^ Arsenic, Axinite, Rhodochrosite, Pyrosmalite, Eryth= 

 rite, Melanterite, Kermesite, Hyalite, Apophyllite in choice cabinet specimens at reasonable prices, will 

 be pleased to answer your correspondence, in reference to above, or any other mineral species you may desire. 



WARD'S NATURAL SCIENCE ESTABLISHMENT, 30 to 40 College Ave., Rochester, N.Y. 



To Whom it may concern** 



Geneva, Nov. 24th, 1899. 



J, undersigned, do testify that the ^^ SociM^Genevoise pour la construction d' Instru- 

 ments de Physique et de Mecanigue" has appointed J^AMES G. BIDDLE, Dealer 

 and Importer, of 'Philadelphia., 'Pa., sole agent for the sale of its apparatus in the 

 United States and Canada, and request that orders and inquiries for catalogues, 

 etc. , he addressed to him. 



SMr.middte's address is (Signed) TH. TURRETTINI, 



Director of the SociMd Genevoise. 



1034 Dreiel Building, Philadelphia. 



>ViA'Y 6 1900'/ 



v4', 



l^al Wu|| 



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