46 Aquatic Lite 
than air, and in consequence the expos- 
ure should be longer. 
For picturing aquatic plants an ordi- 
nary tank containing nothing other than 
the subject will often give excellent re- 
sults. But to show the structure of the 
plant in general, it 1s good practice to lay 
it upon a white sheet on the floor and 
photograph from above. This will give 
The Egyptian Mouthbreeder 
Haplochromis strigigena 
a sharp picture of the entire plant, which 
will serve as well as a drawing for pur- 
poses of identification. Views showing 
the exposed portions of floating plants 
are taken like an ordinary photograph, 
the camera being pointed slightly down- 
ward. 
The most difficult subjects are living 
fishes, particularly the smaller species. 
After considerable 
found that a 
necessary. Briefly, it consists of a very 
narrow tank, which keeps the fish in 
focus automatically, an adjustable back- 
ground, the camera, and a suitable sup- 
experimenting | 
special apparatus was 
port for all. The camera is equipped 
with a copying lens costing thirty cents, 
which enables one to take pictures life 
size and over. The exposed glass side 
of the aquarium is the same size as the 
photographic plate, so that when the 
camera is focused to take in this area it 
is working at full size. The background 
is a piece of heavy cardboard tacked to 
a strip of wood. It can be moved to any 
desired position. The apparatus is sup- 
ported on a long board, which rests on 
an ordinary tripod. The device is porta- 
ble, allowing one to follow the sun or 
carry it to another conservatory. 
Inasmuch as all cameras are not alike, 
the apparatus must be made to conform 
to the particular instrument used. Below 
is a detailed description of the apparatus 
made for the camera described: 
The base is a board three-fourths of 
an inch thick, two feet long and six inches 
wide. A hevagonal nut is firmly mor- 
tised in the centre. The screw in the 
head of the tripod fits into this nut and 
holds the board rigid. Near one end, the 
exact position depending upon the tripod 
socket in the camera, is bored a simple 
hole, through which is thrust a thumb- 
screw to engage the socket in the camera. 
The board is varnished to improve its 
appearance. 
The aquarium measures two by five by 
Salvinia species 
six inches over all. The frame is made 
of gauge 20 galvanized iron strips, one 
inch wide, and bent at right angles length- 
wise. Soft tinned rivets were used to 
put the strips together, but it could just 
With the outside 
measurements given, the exposed glass 
The 
leg of the angle that overhangs the top 
as well be soldered. 
on the sides is four by five inches. 
is cut down to about a quarter inch, so 
that it just protects the raw edge of the 
