138 PBACT1CAL PHOTO-MICKOGKAPHY 



parts, the front circular portion supporting the microscope, 

 and the hind part serving as a support for the camera. The 

 focussing- screen of the camera as well as the front are adjust- 

 able, and can be set in any position on the supporting-rod, 

 and by means of a groove in this rod the parts are prevented 

 from rotating, only having freedom of movement in a vertical 

 direction. The bellows are fixed to the frame carrying the 

 focussing- screen by a hinge and catch, so that if the catch is 

 loosened, the bellows drop down at one side, and the image 

 of the object may be viewed on a dead- white reflecting- screen 

 if desired. Vibration of the supporting- rod is prevented by 

 having two telescopic struts which are supported at their lower 

 end from the corners of the base- plate, and which can be loosened 

 when any alteration of camera-length is necessary. These may 

 then be clamped at any position when the desired length of 

 camera is obtained. 



When arranged similarly to Fig. 47 b, but in the vertical 

 position, it is also available for photographing large objects, any 

 suitable lens simply being screwed on to the front of the camera 

 in the ordinary way. An additional camera-front is supplied 

 for carrying the flanges of any such lenses. Two focussing- 

 screens are supplied, one ground- glass and the other plain glass, 

 as with other cameras. The base-plate supporting the micro- 

 scope rests on three levelling- screws, and can be clamped down 

 when once the microscope has been adjusted in position in 

 relation to the camera. It can also be entirely removed 

 should the camera be required for other purposes. This base- 

 plate, carrying the microscope, can also be rotated so that the 

 camera is available on either side of the operator. The 

 illuminant and optical accessories are carried on the optical 

 bench in the same way as in the larger horizontal camera 

 already described. The optical bench has a pin at one end 

 which drops into a hole in the base- plate, so that it always 

 returns to its proper position in relation to the microscope. 

 The other end of the optical bench is supported on the table on 

 which the apparatus rests. 



Arrangements are also made for altering the position of the 

 optical bench according to whether the camera is required in a 

 vertical or in a horizontal position. It may be used in the hori- 

 zontal position for macrophotography , for the photographing of 



