SCIENC 



New Series 

 Vol. L, No. 1291 



Friday, September 26, 1919 



S1NG1.E Copies, 16 Crs. 

 Annual Subsobiption, $5.09 



Combined Balopticon for Lantern Slides and Opaque 

 Objects. Price, $150.00 



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BALOPTICON 



THE PERFECT STEREOPTICON 



with its technically cor- 

 rect optics and brilliant 

 illuminating system will 

 give you the most satis- 

 factory results possible to 

 obtain on the screen — 

 whatever the form of pro- 

 ject on. There is a model 

 for every purpose, simple 

 in construction and al- 

 most automatic in oper- 

 ation. 



Our greatly enlarged facilities, now being released from 

 important war work, will enable us to increase production 

 in this line. Under present readjustment conditions, how- 

 ever, it will be to your advantage to anticipate your re- 

 quirements as far ahead as possible. 



Write for catalog, with revised price list, and enter 

 your order now for fall delivery. 



New York 

 Chicago 



Washington 

 Rochester, N. Y. 



San Francisco 

 London 



Leading American Makers of Photographic Lenses, Microscopes, Projection 

 Apparatus (Balopticons), Ophthalmic Lenses and Instruments, Photomicro- 

 graphic Apparatus, Range Finders and Gun Sights for Army and Navy, 

 Searchlight Reflectors, Stereo-Prism Binoculars, Magnifiers and other High- 

 Grade Optical Products. 



