102 NATURE-STUDY REVIEW [7:4— Apr., igir 



in length by nine inches wide and one inch thick. Across the bot- 

 tom on the under side of the board screw three battens, one at 

 each end and one in the middle, — this to prevent warping. Now 

 take a piece of wood two feet long and the same width as the 

 baseboard, and with iron brackets twelve inches long fasten it to 

 the baseboard in a vertical position as near to the end of the 

 baseboard as possible. This will serve to hold the camera in 

 an inverted position for use in taking photo-micrographs and 

 also in the photography of large objects such as crabs and shells.. 

 Along the outer edges of the baseboard screw pieces of wood two 

 feet long and one and one-half inches wide with upper edges 

 projecting one-half inch above the baseboard. This will serve 

 as a track in which a platform twelve inches long and about two 

 and a half inches high may slide. This platform carries the cam- 

 era and serves for taking photo-micrographs with the microscope 

 in a horizontal position, and also for the photography of objects 

 such as sea anemones in tanks which may be placed on a small 

 shelf screwed on the vertical board. As in taking photo-micro- 

 graphs the lens of the microscope replaces the camera lens, some 

 arrangement must be made for this. The simplest way is to make 

 a lens board which accurately fits the camera and in which a hole 

 is bored which fits the tube of the microscope. In the sliding 

 platform, bore a hole which will take the tripod screw to fasten 



the camera firmly to 

 the platform. In the 

 vertical board, bore 

 holes which will take 

 the tripod in an invert- 

 ed position. After the 

 apparatus is built, it 

 should be painted well 

 with a dull black paint. 

 The next thing is 

 the standardizing of 

 the apparatus. By trial with the photographic lens, see what 

 position the camera must be in to make negatives one-quarter, 

 one-half, three-quarters and full life size. With the microscope 

 and camera, try out the various objectives and eyepieces and note 

 the size of the circle when the object is accurately focussed on the 

 ground glass. With the aid of small labels pasted on the base- 

 board and vertical board, the various camera positions may be 

 indicated. Now typewrite the data on a sheet of thick paper and 

 keep handy for reference. 



