SCIENCE;"" 



Synchronize Your 

 Hearers' Minds 



Some minds visualize word pictures more slowly than others — and differently. 

 Keep them together and uniform. Illustrate your talks and lectures with actual 

 pictures of your subject matter projected on a screen by the 



BAUSCH 8C LOMB BALOPTICON 



The Perfect Stereopticon 



Balopticons project opaque objects, such as photographs, post cards, colored 

 prints, sketches, printed cards, specimens, etc., as well as slides. The freedom 

 from trouble, the even, steady safe illumination of the new gas-filled Mazda 

 lamp, and the ease of operation make it worth while to specify the Bausch & 

 Lomb Balopticon. 



Bausch ^\pmb Optical (g. 



552 ST. PAUL STREET ROCHESTER, N.\^ 



NEW YORK 



CHICAGO 



WASHINGTON 



SAN FRANCISCO 



LONDON 



Makttt of Photographic Lensa, Microscopes, Projection Apparatus (Balopticons), Ophthalmic 

 Lenses and Instruments, Pholomlcrographic Apparatus, Range Finders and Gun Sights for Army and 

 Nacy, Searchlight Reflectors, Stereo-Prism Binoculars, Magnifiers and other high-grade Optical 

 Products. 



