6 A MARINE AQUARIUM. 
black; an ornamental rim of polished Spanish mahogany was made to sit 
on the edge of the tank; acurtain was hung to conceal the pump; and 
the room generally made presentable. 
By the end of September the whole was in place, and water was 
admitted into the Tank. Not till the last of October, however, were 
organisms admitted, in the forms of growing Algsw and Fishes. For it 
must not be supposed that all went quite smooth. The pump would not 
draw at first ; we found that the pipes leaked, and would not deliver, till 
we had had much labour. Then the pump would “go back ;” the water 
retiring from the barrel sooner or later, after the pumping had ceased; 
so that sometimes it required more than a hundred strokes of the handle, 
before the water would rise. This difficulty still continues, in a mitigated 
form; itis the only one which we have never quite overcome. Then 
the siphon would not act at all for some time ; but, after several months, 
one day, quite suddenly and unexpectedly, it acted perfectly, and has 
gone well ever since. 
As soon as we were in regular work, I found that my supply of water 
was inadequate. Some had been wasted, too; some had leaked in the 
imperfect fitting of the pipes’ joints. Accordingly a further quantity was 
brought up, which made my stock as follows:—Reservoir, 180 gallons; 
Cistern, 60; Tank, 40; equal to 280 gallonsin all. And this quantity 
has never since needed to be replenished. Its quality seems to have 
steadily improved. Clear and bright as it was at first, and faultless as it 
seemed for the sustentation of animal life; it is very perceptibly better 
now. However it be explained, many creatures that would not live more 
than a few weeks, or even days, a year ago, now continue without 
difficulty, often coming into sight months after their introduction, in full 
health and beauty. 
The manipulation is as regular as clock-work. On Tuesday, 
Thursday, and Saturday evenings, my servant pumps till the warning- 
pipe streams, averaging some 675 strokes. If the larger-bored jets are 
on, there must be supplementary pumping in the intercalated days, to a 
varying amount. For Fishes and the higher Crustacea, &c., we find the 
fuller supply of jet No. 1 requisite, and this profusion takes at least 250 
strokes on each of the intercalated days. The total of 675 strokes is 
performed in about half an hour. 
The jets I use are four; of which the orifices, perfectly true and 
round, graduate from the thickness of a lady’s medium pin (No. 1) to that 
of a cambric needle, (No. 4). With No.1, 18 pump strokes deliver an 
hour’s supply of water into the Tank; with No. 2, about 10 strokes; 
with No. 3, 5 strokes; and with No. 4, about 34 strokes. The orifice of 
each jet is just an inch from the surface of the Tank. A white cloud of 
dust-like air-bubbles is driven perpendicularly downward (about a foot 
with No. 1), after which they can still be followed, with a lens, careering 
to every part of the Tank. 
This communication has already reached a length, which I greatly 
fear will be considered tedious. I will not then attempt to narrate my 
experience, as a Naturalist, in the use of the Aquarium for upwards of 
two years. Suffice it to say, it has been a great success; and has amply 
proved the value of the principle of its construction, viz., perpetual 
circulation, with a large reserve of water. One point I will add, which 
may interest some :—The total cost was covered by £60. 
Sandhurst, Torquay, Noy. 20, 1878. 
