PHOTOGRAPHY OF AQUATIC ANIMALS. bi 
order to bring the camera to bear on the object to be photographed, it was then 
necessary to provide a way to determine when the image of the object appeared in 
the desired position in the finder. This was accomplished by using a metal tube open 
at both ends, one end of the tube being placed over the ground glass of the finder 
and the other, which extended above the water, being applied to the eye. The tube 
excluded the light from the space between the eye of the observer and the finder, 
while at the same time the water within it was protected from agitation. By this 
means it was possible to see clearly the image on the ground glass of the finder. 
It was necessary merely to manipulate the handle controlling the shutter in order 
to begin and end the exposure. The plate could then be changed by manipulat- 
ing the rod at the back of the box and another exposure made at once without 
taking the camera from the water. Where it was possible to operate near shore, 
it was unnecessary for the operator to put on the diver’s suit or to enter the water. 
He could set the camera in place from the shore and adjust it or make the exposure 
while lying upon the bank. Boutan, indeed, made satisfactory photographs of 
fixed animals in aquaria by immersing this apparatus in an indoor aquarium and 
operating it by means of a string. By using a very small diaphragm he was able 
to get clear images of objects at a distance of 15 centimeters from the lens, but 
this required an exposure of three minutes. Te obtained photographs of fish and 
other mobile forms in the same manner by inclosing the animal to be photographed 
in a glass globe, which was then immersed in the aquarium at a suitable distance 
from the lens. The globe served to restrict the movements of the animal. When 
working in shallow water, he found that the alge which appear everywhere in the 
submarine landscape were in constant motion whenever there was any movement 
of the water. It was therefore necessary to restrict operations to those days on 
which it was perfectly calm. 
In order to obtain photographs at depths at which it was impossible to wade 
Boutan made use of the diver’s outfit. Te describes the outfit in detail and the 
method of using it in a very interesting section of his paper of 1898. The method of 
procedure was briefly as follows: The boat containing the apparatus to be used 
(diver’s suit, air pumps, and photographic apparatus) was first firmly anchored at the 
spot selected and held in place by means of cables stretched to the rocks on shore. 
The photographer then put on the diver’s suit and descended to the point selected as 
the center of operations, THe first signaled to an assistant to let down the photo- 
graphic apparatus, which consisted of the tripod, the box containing the camera, and 
a weight intended to steady the apparatus. He then sought out the view to be 
taken and set up the apparatus at his leisure. This accomplished, he opened the 
shutter of the camera and signaled to the assistant that the exposure was begun. 
Since it was impossible to use a watch while under water it was necessary that the 
assistant in the boat above should time the exposure. At the expiration of the 
time agreed upon the assistant signaled and the photographer closed the shutter. 
When the weather was good and the sun shining an exposure of ten minutes was 
necessary with a small diaphragm at a depth of 5 meters. Boutan estimated 
that at a depth of 10 meters this exposure would need to be more than doubled. 
