636 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. [6] 



and the other parts of the buildiug, reference may be made to the an- 

 nexed plan, with scale and some of the dimensions stated. Nos. 1 to 

 41 indicate the tanks. 



The retiring rooms and kitchen lie to the north of the hall. The long- 

 est of the three corridors extends 220 feet and is broken by a vestibule 

 55 by 45 feet. 



The roof is groined and constructed of variegated bricks. It rests 

 upon columns of Bath stone, polished serpentine, and Aberdeen gran- 

 ite. There are 21 tanks in the first two series. They increase in size 

 from 11 by 10 feet upward, the largest measuring over 100 feet long by 

 40 feet wide and holding 110,000 gallons of sea water. This is the larg- 

 est tank in the building and is reserved for such large marine speci- 

 mens as porpoises, congers, turtles, &c. The next largest tank is 50 

 feet by 30 feet. The whole of the tanks, 41 in number, are numbered 

 consecutively, commencing on one side. The glass plates for these 

 tanks are of necessity very strong and heavy, being not less than one 

 inch in thickness. 



The salt water is taken directly from the sea by pumping and is run 

 into reservoirs under the floors of the corridors, from which it is again 

 pumped by the same steam-engine, and delivered to the tanks as required. 

 The reservoirs hold 500,000 gallons of water. In the tanks the water 

 is constantly aerated and kept in circulation by a stream of compressed 

 air supplied to the lower part of the tanks. It is forced in by the steam- 

 engine. This system allows the water in each tank to be heated sepa- 

 rately, and is found in many respects preferable to the method of obtain- 

 ing circulation by means of pumping. It permits circulating reservoirs 

 to be dispensed with. The temperature of the water is kept down and 

 the impurities are oxidized by the air. 



The second corridor is about 160 feet long. One side of the eastern 

 portion is assigned to the fresh-water animals. The ofiSces for the cu- 

 rator and naturalist are beyond. These are fitted up with open tanks 

 and every convenience for the nursing and care of the fish which require 

 treatment before being i^laced in the large tanks. 



The conservatory and fernery are two great additional attractions to 

 the establishment. They are approached from the western corridor. 

 The rock work is here remarkably well executed in imitation of ledges 

 of red sandstone. It is all formed of chalk and cement colored red, and 

 is so well done that few persons would for a moment question its being 

 a natural outcrop. Ferns grow in the clefts, and on projecting tables 

 of the rock. There is also a stream of water, broken at intervals by 

 cascades and ponds, utilized for the seals and the larger reptilia. 



In addition to the large tanks, there are numerous smaller or table 

 tanks for the reception of some of the smaller and more rare marine 

 animals. There is also an exhibition of the apparatus for hatching and 

 developing trout and salmon. 



