SCIENCE 



New Series 



Vol. LVI, Xo. 1446 



Friday, September 15, 1922 



Annual Subscription, $6.00 

 Single Copies, 15 Cts. 



Bausch & Lomb 



Observation Telescopes 



AMERICAN-MADE instruments of the highest 

 grade, more moderately priced than other makes of 

 corresponding quality — equipped for both ■ terrestrial 

 and astronomical observations and providing a range 

 of powers from 24x to 120x. 



As an item of school or college equipment, one of 

 these telescopes adds point and zest to many other- 

 wise prosaic courses. They can be used satisfactorily 

 in astronomy, giving sutftcient magnifications for ac- 

 curate observations. 



Three models are offered — with objectives of 60 

 mm (2^ in.), 80 mm (3^ in.) and 102 mm (4 in.) 

 free aperture. 



JJ'ritc for our fully illustrated, dcscriptiz'c booklet. 



Bausch & Lomb Optical Company 



409 St. Paul Street, Rochester, N. Y. 



New York Washington Chicago San Francisco London 



Leading American Makers of Optical Measuring In 5tniments, Photomicrographic Apparatus, Photographic 



Lenses, Microscopes, Projection Apparatus (Balopticons), Ophthalmic Lenses and Instruments, 



Range Finders and Gun-Sights for Army and Navy, Searchlight Reflectors, Stereo-Prism 



Binoculars, Telescopes, Magnifiers, Automobile Lenses and other High-Grade 



Optical Products. 



StP J t 1922 •>?] 



