162 MARVELS OF FISH LIFE 
with a stick. In a photograph the thickened water in 
the second tank is invaluable from a pictorial point of 
view, for it gives the picture its watery appearance. 
Care must be taken to arrange the tanks so that 
when the photograph is taken the glass of the tanks is 
at right angles to the direction of the sunlight. 
If the sun is shining, photography of the specimen 
placed in the front tank may be proceeded with at 
once. But if the sun is not shining, it is far better to 
postpone operations until the following day, or until 
the sun does shine. The reason for this is that with 
a dull light and thickened water in the second tank the 
image of the photographer and the camera are reflected 
in the glass. Further, it is difficult to get sufficient 
exposure with a rapidly swimming fish, except in sun- 
light. 
Presuming that the sun is shining and the scenic 
portion of the picture has been arranged to complete 
satisfaction, all that remains for consideration is the 
fish. Possibly it may be swimming about, and, if so, 
nothing further is required; but more probably the 
specimen is still sulking on the bottom. To induce 
the fish to swim, the water should be stopped from 
running through the tank, and after ten minutes sud- 
denly turned on at full force. This will frequently 
stir up the fish, and he will swim round, heading to- 
wards the stream, thus giving the photographer an 
opportunity to obtain a snap-shot. As an example 
of a photograph obtained in this manner, I would refer 
