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 suflflcient 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 fioor 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. 



