SCIENCE 



New Series 



Vol. TjV, No. 14.33 



Friday, June 16, 1922 



Single Copies, 15 Gts. 

 Annual Subscription, $0.00 



The Balopticon at 



the Summer School 



will be found a great aid m mten&ifymg mteiest, so 

 necessary in covering the amoimt-of^vork scheduled 

 for so short a term. 



Bausch & Lomb 



The Perfect Stereopticon 



will project any opaque subject that 

 the large object holder will accom- 

 modate. Snap shots, maps, speci- 

 mens and colored pictures, as well 

 as lantern slides, can be projected 

 by this efficient machine. Well built 

 and free from operating difficulties 

 the Balopticon with its Mazda lamp, 

 is a worthwhile investment. 



WRITE FOR DESCRIPTIVE CIRCULAR. 



B^usch ^ Ipmb Optical (5, 



552 St. Paul Street Rochester, N. Y. 



New York Washington Chicago San Francisco London 



^Leading American Makers of Microscopes, Projection Apparatus (Balopticons), Photo- 

 graphic Lenses, Ophthalmic Lenses and Instruments, Photo-Micrographic Apparatus, 

 Range Finders and Gun Sights for Army and Navy, Searchlight Reflectors, Telescopes, 

 Stereo-Prism Binoculars, Magnifiers and Other High Grade Optica! Products. 



