110 NEW YORK ZOOLOGICAL SOCIETY 
Most of the enlarged tanks have already been lined in part 
with rockwork, and this treatment will be resumed when a new 
supply of material can be obtained. 
Another improvement effected by the employees under the 
direction of the foreman, was the lowering of six wooden re- 
serve tanks to a level where they are more accessible to the 
attendants who care for them. Their original high position, with 
their bottoms two feet above the floor of the service gallery, made 
them difficult to reach. 
A matter of importance connected with the work of enlarg- 
ing tanks was the locating of several small leaks in the masonry 
which appear to account for the loss of a considerable amount 
of water from the reservoir. It is believed that the last of these 
leaks has been discovered. 
Refrigerating Plant.—Aside from the enlargement of cer- 
tain exhibition tanks, the most important improvement of the 
year was the removal of the refrigerating engine and condenser 
from the interior of the building to the top of the wall back of 
the pump room. Advantage was taken of the change to abandon 
the bulky tank and coil system, and install a condenser of the 
modern double-tube type, which requires less space and gives 
better service. The removal of this machinery became necessary 
in order to comply with requirements of the Fire Department 
for the special housing-in of ammonia-using equipment. 
Photographs of the room constructed for the refrigerating 
plant and an interior view are presented herewith. The work 
of dismantling the plant was done by the Aquarium force. It 
was housed and installed under the direction of the Park De- 
partment, for which work an appropriation of $1,500 was se- 
cured from the City. It was in use during the past summer in its 
new position, and gave satisfactory service. This water cooling 
equipment is operated for about six months only—May to No- 
vember—and its use is to reduce the summer temperature of 
fresh water flowing to tanks containing salmon, trout and 
other northern fishes, including eggs and young fry in the fish 
hatchery. 
The space made vacant by the removal of the refrigerating 
plant has already been utilized by the enlargement of two ex- 
hibition tanks. 
