THE ZooLocist—May, 1876. 4917 
five to one—for the great London Aquarium now preparing to be 
opened at Westminster, where the circumstances are quite different 
to those at Manchester, and where the aquarium is not, as at West- 
minster, placed in the very midst of a great city, with a soot-laden 
atmosphere. Moreover, in this latter aquarium, some of the tanks 
measure twenty feet wide from back to front, being more than in 
any other aquarium where the water is maintained in so clear a 
condition as to satisfy my fastidiousness. When this width is so 
great, the size of reservoirs must be relatively increased, because a 
very small addition of foreign matter in suspension or solution 
then increases the apparent turbidity. Moreover, the Westminster 
building itself is not exactly such a one as I should prefer for an 
aquarium, if I could have controlled it, with reference to all things, 
but as it has to be used for many other purposes I must make the 
best use of it that I can for my purpose. It is, in effect, a huge 
conservatory of glass and iron, supported on brick walls, and, in 
spite of much good ventilation, it will be very hot in summer. 
Yesterday, for example, was a cold and blowing March day (the 
9th), with strong sunshine, and at noon the temperatures were 
thus :— 
External air, maximum—true temperature - : 55° OF. 
in minimum cs - - SOgayt 
Internal air in Westminster Aquarium building - Gers 
Water in reservoir of Aquarium, at bottom - - AGT 
He S at top - - - 50°5 ,, 
Water in Crystal Palace Aquarium everywhere - = #094 4, 
This water at Westminster was fresh water, used to test the sound- 
ness of the reservoir, and as it had been in for ten days, it had had 
time to assume its normal temperature, and it was ten feet deep 
vertically. No water was in the show-tanks, and no circulation 
was going on. This indicates, clearly, that a valuable equalising 
effect will be gained by the reservoir, which these figures show is 
not at all too large; in fact, I tried to get it made to hold a million 
gallons, instead of only about 600,000 gallons. Really such a 
reservoir cannot be too great for the general purposes of an 
* It will be seen that the Crystal Palace water is higher than that in the West- 
minster reservoir, because the show-tanks above are exposed to warmth, while at 
Westminster there are at present no show-tanks to raise the temperature of the 
reservoir. The minimum of the external air was for the previous twenty-four hours. 
The instruments used were made by Negretti and Zambra. 
SECOND SERIES—VOL. XI. Pas) 
