840 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



scopes placed in their Lauds [" instrument tres solide pour etre mis 

 outre los maius dcs eleves et eviter le devissage dcs objectifs" *). 

 The objectives are attached to a revolver so that they cannot be un- 

 screwed, neither can the lens-cells bo removed. The revolver con- 

 sists of an angle-plate shaped like a sector and suspended in front 

 of the body-tube to swing on its centre, so that either objective can 

 be brought to the axis of the body-tubo. The brass mounts of the 

 objectives are so arranged that the foci are approximately in tho 

 same plane. 



Nachet's Photo-micrographic Microscope. — M. Nachet's Micro- 



Fig. 159. 



scope and camera complete are shown in fig. 159, and an enlarged 

 view of part of the Microscope in fig. 160. 



Fig. 160. 



The Microscope has a special arrangement for allowing the image 

 to be viewed in the eye-piece previous to its projection on the ground 



* Op. cit., p. 17. 



