PHOTOGRAPHING FISH 



93 



rubber will come in contact so tightly that leakage 

 will be impossible. The wood should be thoroughly 

 shellacked be- 

 fore being put 

 together. 



The glass Ci 

 must be of the 

 best white plate, 



Fig. i. 



free from bub- 

 bles and imper- 

 fections. The thickness of it depends on the size of 

 the aquarium ; one twenty-six inches in length would 

 require the glass to be quite a quarter of an inch thick. 

 If no plate-glass is obtainable, a mirror can be 

 cleaned, and, if a good one, will be found to answer 

 perfectly. 



The method of fastening in the glass is shown in 

 this diagram. The rubber tube A (Fig. i) is laid 

 in the groove and the glass pressed tightly against it 

 by a batten of strong wood such as oak ; this, when 

 screwed in place, will hold the glass. The batten 

 should be bevelled, as shown in the diagram C 

 (Fig. i), in order to prevent its being reflected in 

 the glass. On the upper side of the glass no batten is 

 needed unless the tank is very large. The batten has 

 the disadvantage of casting a shadow, which shadow 

 usually falls on the fish. Heavy copper wire tightly 

 twisted and attached to two strong screw-eyes will 



