J^o^ 



U'Cf 



SCIENCE 



Annual Suesceiption, $5.00. 



General Electric Co/s 



FLUOROSCOPES 



Platino^cyanide of Barium, or Tungstate of Calcium Screens. 



NEW X=RAY TUBE 



WITH AUTOMATIC 



VACUUM REGULATOR. 



EFFICIENT. LONG-LIVED. 



ROENTGEN RAY APPARATUS of all kinds. 



Catalogue No. 90S0. 



Candelabra, Miniature and Decorative Lamps. 



Catalogue No. 9044. 



Edisoii Deorative aDd piliilatDre Lamp oeDailieiit, 



(GENERAL ELECTRIC COMPANY,) 



HARRISON, N. J. 



Tnvai'f oVkTof A mna^inlflfie Large and small examples of NAUTILOS with 



XII y Kl \jK in a liM (3pt?l7iai HCgi. sectioned shell, and animal in place, price ?7-S12 ; 

 thie rare and beautiful METACRINU.S from Japan, 24-30 inches long, S14-S16 ; model showing 

 anatomy of the PRECIOUS COKAt, S12 ; accurate life-size model of OCTUPUS that spread 25 

 feet, and of GIANT SQUID 39 feet in length. Write for circulars. Also large General Inverte- 

 brate Stock, Systematic Collections, Zoological Charts and Biological Supplies. 



"Ward^s Natural Science Establisliiuent, 



18 to 28 College Ave., Rochester. N. T. 



New Catalogues of Scientific Apparatus. 



No. 245. "Standard Apparatus for Electrical Meas- 

 urements. ' ' 

 No. 250. " Ideal Projection Lanterns and Improved 



Focusing Electric Lamps. ' ' 

 No. 255. "The Rosa Curve Tracer." 

 No. 260. " Net Price List of X-Eay Apparatus." 

 No. 265. "The Rowland Eleotrodynamometer. " 



No. 270. " A Few Specialties for Colleges and 

 Schools. ' ' 



No. 275. "Condensers, — Standard and Commer- 

 cial." 



Cat. A. " The Chloridn Accumulator." 



Cat. X. "Weston Standard Voltmeters, Ammeters, 

 Wattmeters, Etc." 



Write for such as interest you, but do not think that this list represents the entire scope of my trade. 

 I am a business helper to the buyer of scientific apparatus. I make a specialty of " Duty Free " Importations 

 from Europe. It will cost nothing to ascertain if I can assist you. Correspondence solicited. 



JAMES Q. BIDDLE, 909 Drexel Building, Philadelphia. 



