SCIENCE— ADVERTISEMENTS 



Model D Balopticon with 19^-inch optical bed-$67.50 



The Superior Quality 

 of Sausch£Lomb len- 

 ses, microscopes, field 

 glasses, projection ap- 

 paratus, engineering 

 and other scientific in- 

 struments is the pro- 

 duct of nearly Sixty 

 Year's Experience. 



The Ideal Lantern 

 for the Physical Laboratory 



This lantern is ideal for the physical laboratory because 

 of its rigidity and high-grade equipment. 

 The accurately milled optical bed and the clamping 

 blocks for the supports carrying accessories assure absolute 

 alignment. The Model D 



pauscK |omD 



^alopticon 



is fitted with triple condensing system, permitting use of 

 parallel, convergent or divergent light. 

 All attachments such as projection microscope, polari- 

 scope, opaque attachment, etc., may be added as desired. 



Extra supports and accessory bed may be secured 



DESCRIPTIVE CIRCULAR ISD SENT ON REQUEST 



Bausch ^ Ipmb Optical (5. 



NEW YORK WASHINGTON CHICAGO SAN FttANCISCO 



LONDON I^OCHESTEa,N.Y. ^RANKrORT 



