JAMES SWIFT & SON L™. 



Makers of the Highest Grade 



MICROSCOPES and ACCESSORIES 



Contractors to all Scientific Departments of H.M. Government. 



ILLUSTRATED DESCRIPTIVE CATALOGUES 



Penological Microscopes 



giving specifications of various models, 



AND 



Penological Accessories 



and Instruments for Mineralogy and Crystal- 

 lography, including Kefractometers, Gonio- 

 meters, Recording Micrometers, etc., 



will be sent post free on request. 



University Optical Works 

 81 TOTTENHAM COURT ROAD, LONDON, W.I. 



Teitz 



PETROLOGICAL 

 Ml 



A few of the special features are =— 



(1) Anastigmatic Tube Analyser, giving enhanced definition. 



(2) Unique and Superior Centring Objective Changing Device. 



(3) Wide Body Tube, taking eyepieces 30 mm. diameter, giving- 



large field of view. 



(4) Choice of various pattern Substages and Polarising Prisms. 



(5) High and unsurpassed standard of Optical and Mechanical 



Efficiency. 



Catalogue post free 



OGILVY & CO. 



(British Agents for E. Leitz) 



18 BLOOMSBURY SQUARE, LONDON, W.C. 



