TWENTIETH ANNUAL REPORT 103 
The condition of the water pumped from the Harbor has 
grown appreciably worse since the Zoological Society took 
charge of the Aquarium in 1902. It became unusually foul dur- 
ing the past summer and the last porpoise, which lived 21 
months in the building, died from sheer filth infection. It being 
impossible under present conditions, to supply these large pools 
in any other way than from the Harbor, the filtration of the 
water became absolutely necessary. This matter has been con- 
sidered nearly every year but abandoned owing to the difficulty 
of finding a place in this over-crowded building to install filters 
of sufficient size. It was necessary to take two of the large 
tanks, above the pump room, used to furnish a strong head to 
these pools but as the pumps are always in operation it was de- 
cided to convert them into filters and get along with the supply 
furnished by the pumps alone. 
The new filters were put in operation on October 3 and 
the effect of their use has been satisfactory beyond our expecta- 
tions. The harbor water is now delivered to the floor pools in 
quite as clear condition as the stored sea water used in the glass- 
fronted tanks. 
A surprising amount of dirt is floated from the tops of the 
filters when they are washed twice a week. Although the dirt 
has certainly been taken out of this water supply, its salinity is, 
of course, as low as ever. It is also probable that the water still 
contains bacteria but this danger may perhaps be eliminated 
by the use of limited quantities of copper sulphate. In any event 
the water is entirely clear and is undoubtedly more wholesome 
for the occupants of the pools. 
The general appearance of the interior of the Aquarium 
building has been much improved by painting, a single coat of 
paint having served to freshen the surfaces of ceiling, walls and 
pillars. This work also included offices and the service gallery 
as well as the main exhibition room. White paint in the service 
gallery and on the facings of the skylights has had the effect of 
considerably improving the lighting of the exhibition tanks. 
A new dark room in the laboratory and two new toilet 
rooms recently completed, were improvements much needed. 
Several square yards of cracked floor tiling have been replaced 
to good effect. The ventilating ducts under the balconies have 
been extended to the full length of the balconies and the troughs 
of the fish hatchery have been renewed. 
