crosGopes 



50 Styles to Select From 



Journal of Applied Microscopy $1.00 Per 

 Year 



Laboratory Apparatus 



For All Purposes 



Photographic Lenses 



For Ordinary and Microscopic Purposes 



Chemicals 



AND CHEMICAL APPARATUS 



Estimates for Import 



Large Stock Always On Hand 



Catalogue of All Lines Free 



Bausch & Lomb Optical Co., 



New York Rochester, N. Y 



'With its head in the clouds." 



PIKES PEAK. 



One of the most famous mountains 

 in America stands about midway be- 

 tween Denver and Pueblo. Forty 

 years ago, it took as many days to 

 reach it as it now takes hours, so 

 improved are the transportation facili- 

 ties. The 



NEW YORK CENTRAL LINES 



and their connections offer fast and 

 luxurious trains with only one change 

 between New York or Boston and im- 

 portant points in Colorado. 



A copy of " America's Winter Resorts," 

 will be sent free, postpaid, on receipt of a 

 postage stamp by George H. Daniels, Gen- 

 eral Passenger Agent, New York Central 

 & Hudson River Railroad, Grand Central 

 Station, New York. 



RADIUM I 



The New Radio-Actlve Element 



We are the sole agents for the New Spinthariscope, re- 

 cently invented by Sir William Crookes for showing the 

 marvelous radio-active properties of radium; also the 

 spinthariscope elides arranged for viewing these phe- 

 nomena with any microscope. Each instrument is 

 complete with particle of radium and flourescent 

 screen for viewing the scintillations. 



The Spinthariscope, pontpntd, • • $9.00 

 ** The Spinthariscope Slide, postpaid, 7.50 

 Duty free prices to schools and coUeBes. Send for circu- 

 lar ; also catalogues of microscopes, stereopticons and shdes. 

 Agents for E. Leitz and K. & J7 Beck Microscopes. 

 Williams, Brown &Earle,Dept. N. OlSChestnnl St.,FbiladelphU. 



^ PSYCHOLOGICAL ^ 



^ APPARATUS ^ 



A list of psychological apparatus supplied 

 to the laboratories of Columbia, Harvard 

 and other leading universities will be sent 

 on application. 



Special apparatus and instruments for psy- 

 chological and physiological research will be 

 made to order. Designs will be submitted 

 for original apparatus. 



E. HORSTMANN, 



546 West 1 25th St., NEW YORK CITY 



