12 THE MICROSCOPE. Jan., 



that of the camera. It will facilitate things to draw a 

 centre line from end to end of the base-board. 



To insure steadiness, hold microscope rigidly in place 

 by its base, cutting holes, if necessary, for the feet, and 

 fastening all down by padded cross-strips of wood held 

 by screws. 



Similarly centre your illuminating apparatus and con- 

 densers, so that an eye placed at the centre of the plate 

 could look directly through and see the ocular, objective, 

 condenseis and flame all in one and the same straight 

 line. 



To secure freedom from jarring and vibration, which 

 spoils too many fine negatives buy three of the hemis- 

 pherical rubber balls with screw attached, sold by all 

 hardware and furniture men to screw into furniture to 

 keep it from marring the wall and woodwork. Make 

 legs of these, putting them in the under side of the base, 

 two under the back of the camera, close to the edges of 

 the board, the third at the centre of the other end. On 

 these three legs the apparatus will stand firmly, even if 

 the table-top, on which it is placed, may not be absolute- 

 ly flat; vibrations also being absorbed, so that a pass- 

 ing "L" train, or beer truck will not disturb the work. 



I have already referred to the joint between the 'scope 

 and camera, and now only add, that while light-tight, 

 it is also flexible enough to allow focussing. 



Eye-pieces may be used, or not, as found best, under 

 conditions described in technical treatises on the subject 

 but it is absolutely requisite that every reflecting point 

 throughout all the apparatus must be suppressed, or fog 

 will result, as exposures are naturally somewhat prolon- 

 ged. This may be well done by rubbing up lamp-black 

 lacquer until a spot touched therewith shows a uniformly 

 dull surface, with no reflection whatsoever when dry. 



Having dabbled in such work for more than twenty 

 years, I have met and overcome the most technical 



