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INSTRUMENTATION 



microscope. The centering telescope is included. The firm of Zeiss, 

 Jena (1949) also supplies a revolving turret substage mount of the type 

 under discussion. The phase condenser, N.A. 0.9, fits into a non-center- 

 ing mount. 



Fig. III. 5. 5. The phase contrast "universal" model microscope available from 

 I. Koristka and Co. Courtesy of I. Koristka and Co. (1949). 



The firm of Galileo (1949) provides phase accessories for its research 

 stand equipped with a pancratic condenser system. The condenser 

 proper is of the achromatic, aplanatic, immersion type, N.A. 1.40, and 

 it is placed in a centering mount. The pancratic system of continuously 

 variable power can change the effective numerical aperture of the 

 condenser from 0.16 to 1.40. The pancratic system is located between 



