1895.] MICROSCOPICAL JOURNAL. 135 



tion. It is doubl}'' right. The " man " sensitizes these plates 

 (wet,) introduces them into the camera, uses his judgment as to 

 exposure, prints and mounts the negatives. The toning forcing 

 and developing these photos are a nice work of skilled profes- 

 sional labor. A non professional may do it. Of course the 

 writer overlooked the professional and exercised his judgment 

 as to development, toning, forcing, printing and mounting. It 

 was found that three persons were fully and thoroughly occu- 

 pied while the work was going on. 



3. The Camera. — Common 1 and i plate cameras were used. 

 The photographic objective was removed from the camera which 

 was mounted upon a base board. This board was made of black 

 walnut thoroughly filled with varnish and polished according 

 to the arts of piano case finishing. 



Its dimensions were : 55 inches in length, 11 inches in breadth, 

 Id inches in thickness. In the longitudinal center tin strips of 

 brass polished, (One inch wide, J inch thick, 55 inches long) 

 were inlaid in such a manner that a slot I inch wide was left 

 between them. The wood of the board underneath the slot 

 was grooved out f inch wide, and i inch deep and 55 inches 

 long. This arrangement gave an exact longitudinal center on 

 which the camera, the condensor, and the microscope are 

 fastened and mounted by strips of ebony ] inch wide that 

 run smoothly in the brass slots attached to the basis of the ap- 

 paratus named. This device holds them in the median line. 

 To keep them from lifting out — strips of brass ? inch wide and 

 2 inches long were attached to the ebony strips so that when 

 placed their upper surface comes in contact with the under sur- 

 face of the 55 inch brass strips. Thus the parts can be shifted 

 backwards and forwards without deviating from tlie median 

 line. 



The camera was set upon a box 11x8x4 inches, attached to 

 the base board of camera by brass slots and T strips. This ele- 

 vation was necessary in order to bring the center of the camera 

 up to the center of microscope. 



4. Sun Light. — This was employed because when available 

 according to Woodward it is the best light for microscopy. It 

 is an annoying light because so often absent and interfered 

 with by clouds, haze, buildings and trees. It requires patience, 



