SCIENCE 



Niw Sbbies 

 Vol. XL. No. 1030 



Friday, September 25, 1914 



Single Copies, 15 Ctb. 

 Annual SuBSOBipiioir, 16.00 



Bausch & Lomb Combined Balopticon 



(NEW MODEL) 



Particularly adapted for use wherever an appa- 

 ratus is desired for projection of opaque objects 

 and lantern slides only — designed along lines 

 found by experience to give greatest efficiency 

 and most convenient manipulation. 



Some advantages: 



(1) Practically instant interchange between 

 projection of opaque materials (photos, 

 postcards, solid objects, etc.) and lan- 

 tern slides. 



(2) Opaque objects always held in hori- 

 zontal position. 



(3) Correct position, left to right, of all 

 images on screen — with only one mirror 

 reflection. 



(4) High grade projection lens of large 

 diameter. 



(5) Direct lighting of opaque object, giv- 

 ing brilliant illumination. 



Price, as illaslrateJ, $120.00. Special terms lo 

 educalional inslHuUons. Send for special circular. 



BAUSCH & LOMB OPTICAL CO. 



552 St. Paul St. ROCHESTER, N. Y. 



NEW YORK: 200 Fifth Ave. 

 WASHINGTON: 613 Fifteenth St., N. W. 

 CHICAGO: 122 S. Michigan Blvd. 



SAN FRANCISCO, 154 Sutter St. 

 FRANKFURT A.M.: G.m.b.H. 31 Schillerstrasse 

 LONDON: 37 and 38 Hatton Garden, E.G. 



