166 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of flie camera may clear the outer tube when it is being lowered. The 
upright is fixed nearly in the middle of the base-board, and the inner 
or sliding tube should be graduated to inches and tenths or millimetres, 
as may be preferred. 
Any good Microscope-stand will serve, but it is essential that the 
fine-adjustment should have a graduated head, and a revolving stage is 
a great convenience. 
The above dimensions are calculated for the largest but one of 
Zeiss’ stands. I have not a catalogue by me, but it is, I believe, deno- 
Fig. 9. 
Camera attached to Microscope. 
minated IIa. In this stand the milled head of the fine-adjustment is 
divided into 50 parts, marked from 2 to 100. If the Microscope which 
it is desired to use be not provided with a graduated fine-adjustment, 
a special one must be fitted, which can easily be done by turning up a 
flat button of hard wood, with a cavity below just large enough to slip 
tightly over the milled head, and with the upper surface flat, on which 
can be gummed a paper disc graduated to 2° or 4°, as may be convenient. 
The provision of an index carried on some part of the arm of the 
