176 MARVELS OF FISH LIFE 
scenic negative are combined to make a single print 
or lantern slide. 
Two tanks are placed on the wooden platform 
already mentioned, and stones and weeds are arranged 
in both the tanks and on the platform. The water 
in the front tank is next stirred up so that everything 
is obscured. By the time this water has partially 
cleared, the weeds (which when first put in were limp 
and drooping) have freshened up. As soon as the 
water has cleared sufficiently to show the weeds in 
the front tank, the first photograph should be taken. 
A second should be taken when the weeds in the tank 
behind it are also showing, and a third exposure made 
when the weeds in both tanks and the stones on the 
platform are visible. In this manner three scenic 
negatives can be obtained from a single tank arrange- 
ment. 
If a dark background is required in order to show 
up a silvery fish, the canvas screen behind the plat- 
form should be thrown into shade by tacking a sheet 
from the top of the canvas background to the top of 
the tank. 
The method of combining a fish negative and a 
scenic negative together so as to make a single print is 
as follows :— 
First make a transparency of the fish negative. 
This transparency will show the fish on clear glass. 
Next carefully block out the whole of the fish with 
colour on the film side of the transparency. Then 
