SIXTEENTH ANNUAL REPORT 103 
by sea-water. The ice machine was thoroughly overhauled in 
preparation for the warm weather. The large underground 
reservoir of stored sea-water has now been in use three and a 
half years. This supply of pure water, circulating constantly 
through the tanks containing marine species, has become an in- 
dispensable feature of the equipment of the institution. The cost 
of keeping it warm enough for tropical forms has been a thou- 
rand dollars a year less than under the old system of pumping 
cold water from the harbor, while its purity as a medium for 
marine animals has greatly reduced the cost of stocking with 
specimens. Several thousand gallons of water are added to it 
each year to replace losses caused by leakage and evaporation. 
With a more perfect system of piping and valves the moderate 
waste by leakage can eventually be eliminated. The frequent 
bursting of the chemical lead steam-coil used in heating sea- 
water is now avoided by the introduction of a galvanized steam 
cylinder covered with lead. 
The explosion of dynamite at Communipaw, Jersey City, 
February 1, 1911, caused much damage to the skylights and win- 
dows of the Aquarium building, breaking more than fifty panes 
of glass. The heavy glass of the skylights fell to the floor in 
many places, but although several hundred people were in the 
building, fortunately no one was injured. The prompt action of 
the attendants prevented any rush for the doors, and order in 
the building was scarcely interrupted. The cost of re-glazing 
amounted to $208.96. 
The Aquarium was opened to the public at night from May 
30, 1911, to September 30, 1911, and the average night attend- 
ance during this period was 1,479. Night opening was made 
possible through a balance available on account of the Director’s 
salary, and six men were added to the force during that time. 
The additional cost for lighting was paid by a transfer from al- 
lowance for fuel. The Aquarium participated in the City Budget 
Exhibit in October, and loaned the same exhibits to the Chicago 
Municipal Exposition. The attendance for the year was 2,011,- 
544, an average of 5,511 a day. The appropriation for the year 
was $48,000, which is just $1,500 more than it was nine years 
ago. The sale of postcards, bulletins and other Aquarium pub- 
lications during the year amounted to $631.81. The illustra- 
