MICROSCOPE AND CAMERA ALLIED 



microscopy and not photography in these pages, 

 there is no need to go into further details. Even 

 the experienced photographer, however, is liable to 

 overlook one or two important details. The bug- 

 bear in all work of this kind, with low magnifica- 

 tions as well as high, is vibration. Not only is our 

 object magnified but every movement is equally 

 increased. No one should walk across the room 

 while this work is in progress; in large towns, 

 trams and heavy motors will ruin many a plate, in 

 fact it is only when one takes up work of this kind 

 that one realises that one's house is in a perpetual 

 quiver. Some enthusiasts work at the dead of 

 night, others suspend their apparatus on springs 

 and invent all kinds of ingenious devices to over- 

 come these miniature earthquakes. 



If time is no object, we have an easy means of 

 still further increasing the magnification. To do so 

 we cut a thin sheet of copper in such a manner 

 that it just fits our lens tube, in front of the 

 diaphragm. Then in the very centre of the copper 

 disc we make a hole with a " number one " 

 needle, the hole is about one twentieth of an inch 

 in diameter. Replace the convex lens in its card- 

 board holder and screw on the front portion of the 

 camera lens. A trial will show that we have con- 

 siderably increased the magnification but decreased 

 the amount of light admitted by the lens, there- 

 fore we shall probably require an exposure as long 

 as an hour. How about the bugbear vibration 

 during such a long exposure is a natural question 



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