376 THE AMERICAN MONTHLY [Dec. 



means of a suitable lens the nicest adjustment can be 

 made. The plate holder is double and fitted with inside 

 kits to carry 3ix4i, 22x2J or lantern plates, in addition to 

 those of its full size, 4x5. 



The front is fitted with a removal plain board to which 

 an ordinary photographic lens may be attached, and an 

 additional board carrying an extension, which may be 

 oblong or cone shaped as desired, with an opening in its 

 front end to receive the tube of the microscope. The 

 flange of the photographic lens can be attached to this 

 extension front if it be necessary to increase the length 

 of the camera in copying and enlarging. 



When the camera is used in the vertical or inclined po- 

 sitions, both coarse and fine adjustment screws are within 

 easy reach of the hand and may be manipulated in con- 

 nection with observance of the focusing upon the screen. 

 But when the horizontal position is assumed, the distance 

 is too great from the screen to microscope to permit this, 

 and other means must be provided. A short rod turning 

 freely in suitable bearings is attached to the base board 

 on right hand side of the camera. To the end nearest the 

 observer is fitted a large milled head and to the other a 

 pulley wheel with V-shaped groove in its periphery, a 

 corresponding groove being also turned in the microme- 

 ter screw of the microscope. This pulley wheel slides 

 freely upon the rod or shaft, allowing it to be placed in 

 line with the fine adjustment screw, where it is firmly 

 held by a small set screw. A fine cord passed around the 

 two grooves suffices to move the micrometer screw, when 

 the milled head is revolved. This of course is an old and 

 well known device, but being a good one has been adopted 

 in this case. 



The extension of the iron carrying frame beyond the 

 end of the baseboard, with the additional weight of the 

 camera acting as a lever, having a tendency to tip the 



