ELEMENTARY PHOTO-MICROGRAPHY. 35 



Both stronger light and longer exposure will 

 now be needed, especially when object is of dark 

 colour, for only that portion of light which is re- 

 flected can act upon the dry plate. A lamp and 

 bull's-eye will do very well, but an incandescent 

 lantern is better still. This is effective and clean, 

 and is got ready with little trouble. It also reduces 

 exposure. A rubber tube connected with nearest 

 gas bracket enables the light to be turned on or off 

 when required. 



This will illuminate large areas in a most satis- 

 factory way, and with less trouble than a lamp ; 

 but the projection lenses must be taken away and 

 the inner 4in. condenser alone used. 



In fig. 10 it will be noticed that the convex 

 side of bull's-eye is turned towards the lantern. 

 The best angle for the light to be thrown upon the 

 slide will be found by experiment. This may be at 

 one time at right angles with centre line of camera, 

 or at another time more as shown in fig. 10. 



For small objects, a silver side reflector of 

 parabolic form will take the rays of light from a 

 lamp and distribute them over the object ; but 

 unless rightly done, one side of object will be sharp 

 and the opposite side fuzzy, owing to deficient 

 lighting ; in other words, one side would be well 

 lighted and the other in shadow. 



With opaque objects under reflected light it is 

 sometimes difficult to avoid reflection from the 



