THE PHOTO-MICROGRAPHIC CAMERA 



139 



bacteriological culture- tubes, or for large objects which are not 

 so easily dealt with when the camera is in the vertical position. 



The procedure when changing the camera from the vertical 

 to the horizontal is quite simple, and is effected by loosening the 

 clamps on the vertical rod, and also on the bracing- stays, 

 which at once allows the 

 camera to be tilted over. 

 The accessory apparatus 

 on the optical bench then 

 has to be brought to the 

 proper height so that it 

 is in alignment with the 

 optical centre of the 

 microscope ; the adjust- 

 ments are the same as 

 in other types of hori- 

 zontal apparatus. 



The extension of 

 camera in this apparatus 

 is not sufficiently great 

 to render it necessary 

 to provide any addi- 

 tional focussing-rod for 

 operating the fine-adjust- 

 ment, so that to obtain 

 high magnifications it will 

 generally be necessary to 

 use higher power pro- 

 jection-oculars. 



Cameras for Special 

 Purposes. With the 

 recent introduction of 

 improved arrangements 

 for illuminating living 

 bacteria and other un- 

 stained objects, by means of the parabolic illuminator of 

 Messrs. Zeiss and the one made by Messrs. Leitz to fulfil 

 the same purpose, it has become desirable at times to have 

 an apparatus which shall be capable of use for photo- 

 graphing such living and moving objects. The essential point 



FIG. 52. Reflex Camera used in combina- 

 tion with Van Heurck Vertical. 



