728 



SUMMARY OF QUERENT RESEARCHES RELATING TO 



Voigtlander and Sons' Stand Vila.*— This small stand (fig. 110) 

 inclines to 45° and has a movable vulcanite sta^e !)0 x 170 mm., re- 



!^!5ti|i^ler. 



Fig. 110. 



volving diaphragm, mirror 55 mm. diameter, and rack-and-pinion 

 fQcnsing adjustment. 



Voigtlander and Sons' Hand Microscope for School and Demon- 

 stration.! — This is a cheap Microscope for class demonstration (tig. 111). 



Fig. 111. 



The focusing is done with the eye-piece tube. There is a rectangular 

 stage and revolving diaphragm. 



fig 



Voigtlander and Sons' Stand I.| — This large model is shown in 

 112. It has complete inclination, rack-and-pinion coarse-adjust- 

 ment, and new micrometer focusing with division of the milled head in 

 0"002 mm. The wide outer tube is of 50 mm. and the large mechanical 

 stage of 130 mm. diameter. The Abbe illuminating apparatus has a 

 swing-out condenser (N.A. 1 • 40), iris diaphragm for oblique illumina- 



* Catalogue (English Edition) 1907, p. 37. 

 X Tom. cit., p. 25. 



t Tom. cit., p. 38. 



