144 



8UMMAEY OF CUEKENT RESEARCHES RELATING TO 



Fig. 35. 



H. A third disc C is supported by B and moves with it. It carries 

 the slide D. A photograph having been taken, with the object inclined 

 in one direction, the carrier is tilted in the opposite direction, and a 

 second one taken. As it is indispensable that the object should be 

 exactly in the plane of the axis of rotation, the disc C is connected 



with B by a piece of tubing 

 having a thread so that it 

 can be raised or lowered. 

 A wedge slipped under one 

 end of the plate B is the most 

 convenient mode of inclining 

 it, a spring being inserted 

 under the other end. Screws 

 are not so good. According 

 to the objective used the 

 angle of inclination for the 

 best eifects varies from 4° 

 with high powers to 12° with 

 low powers. The wedge can 

 be marked at different points, 

 so as to show the angle of 

 inclination. 



In focusing the two 

 wedges, care must be taken 

 that exactly the same details 

 of the object are focused 

 in each case, otherwise the 

 photographs will not com- 

 bine in the stereoscope. 



(Fig. 35 shows the ap- 

 paratus in place on the 

 Microscope.) 



Another form was devised 

 by Prof. G. Fritsch, a de- 

 scription of which, for want 

 of the woodcut illustrating 

 it, must be deferred. 

 Dr. H. Fol has devised * an apparatus (fig. 36) for photographing 

 microscopic objects under small magnifying powers. He considers 

 that such photographs are undoubtedly of much greater value when 

 observed under the stereoscope. 



The table T carries at one end the board B and camera C P, with 

 the supports A. The table is raised and lowered on the tripod by 

 the rack and pinion F H, or moved horizontally by a second one on 

 the further side. The board B turns on a pivot h and the extent of the 

 motion is shown on a graduated scale at the top. It is fixed in any 

 position by S. The camera is double, each bellows being adjustable 

 by the milled heads K K. The object lies in a black cup in water 



Fol, H., Lehrb. d. Vergl. Mikr. Anat., 1884, p. 79 (1 fig.). 



