THE PUBLIC AQUAEIUM 



261 



and the troublesome and expensive process will have to be repeated 

 with painstaking care. 



There are many 1-inch, 7-foot glass plates in the New York Aqua- 

 rium that have been in position for 30 years, testifying to the care 



Fig. 7. — Section of the service passageway in tlie New York Aquarium. Above, sky- 

 lights ; lielow, exhibition tanks ; at right, reserve tanks ; at left alxive, rear sides 

 of exhibition tanks fronting on balcony. The exhibition tanks shown below extend 

 from the glass fronts at left to the wall at right, a distance of 11 feet. The 

 skylights are not large enough ; on dark days the lights over the tanks must be 

 turned on. The vertical windows above are of little value in lighting the tanks 



with which they were placed originally. Occasional breakages in 

 long-set glass may be traceable to gradual rusting in some part of the 

 supporting iron frame, the slow deterioration of the rubber strip, or 

 a gradual hardening of the flexible cement packing around the border 

 of the plate. These conditions can not be ascertained without re- 



