4112 The Zoologist — August, 1874. 



by order of the Committee, some weeks ago, to the managers of 

 existing and projected aquaria, both at home and abroad, in order 

 to ascertain how far our own conchisions are justified or otherwise 

 by their contents. It appears to us to be convenient to consider 

 the subject under two distinct aspects, viz. : — 1st, in reference to 

 the biological conditions of success ; 2nd, to those which are 

 essential to financial success. 



1st. Unfortunately much of the information obtained refers to 

 establishments not yet in active operation. Thus, the Eastern 

 Counties Aquarium Company, Limited (Great Yarmouth), the Liver- 

 pool, Manchester, and Southport Aquaria, are all schen)es as yet in 

 this position. Among aquaria in actual working order we find two 

 distinct systems in use ; tlie one being illustrated in the practice of 

 Brighton, Berlin, and Vienna; the other in that of Hamburg, the 

 Crystal Palace and the Jardin d'Acclimalation in Paris. These two 

 systems are essentially different in principle and in action, and in 

 England are fairly typified in the establishments at Brighton and 

 Sydenham respectively. In the former, there is no actual circula- 

 tion from one tank to another; the bulk of water in the reserve- 

 cisterns bears only a small proportion to that in the show-tanks, 

 and aeration is accomplished by pumping air into the water through 

 vulcanite tubes of considerable diameter. In the latter, on the 

 contrary, a constant circulation is maintained night and day from 

 one tank to another; the bulk of water in the cisterns is about five 

 limes that of the contents of the show-tanks, while aeration is 

 effected by carrying a main over the top of the latter for their 

 entire length, from which, under considerable pressure, a small 

 stream of water pours from a tap into each, breaking the surface of 

 the water, and carrying down into its body countless myriads of 

 air-bubblos, so minute that they float long about the tank before 

 rising to the surface, partaking of the proper motion of its contents, 

 instead of coming almost instantly to the lop, as the larger bubbles 

 of air do at Brighton ; thus they present an enormous oxidizing 

 surface to the water, and as a result its whole mass has a bright, 

 sparkling, almost effervescent appearance. Unfortunately, in the 

 opinion of many competent persons, the Brighton Aquarium is, 

 zoologically considered, by no means a success: the mortality 

 among the animals is said to be great ; the tanks are certainly often 

 turbid ; and sooner or later a general reconstruction of the whole 

 establishment will probably be necessary. The Berlin Aquarium 



