
THE FRESH-WATER AQUARIUM. 135 
work and plants are introduced, than a tank whose shape is 
square; it also gives a better chance for the light to strike 
upon every point inside. 
The facilities for procuring tanks already made are so 
great nowadays, that while once it was an object to know 
how to construct a tank for one’s self, now one has only to 
make a choice from several patterns. The most important 
thing to look after in selecting a tank, next to its material 
and shape, is the kind of cement which has been used ; all 
sorts of putty are to be rejected as worthless; if we cannot 
be sure that the cement is good and not injurious to fishes, a 
few weeks trial, or even less, will convince us of its value. 
Another point to be attended to, is that the cement be quite 
hard before the tank is filled with water, as there are some 
kinds of cement used that never harden; of course, in these 
cases there is danger of having a leaky tank to contend with. 
Of the other kinds of tanks, either those made wholly of 
clay, or of glass, or those with one side at an angle of 50° 
with the base, so as to form a beach, after the pattern of the 
Warington tank, or those with all the sides of slate, in 
imitation of a rock pool, or those of an oval or hexagonal 
shape, each has its advocates. Some tanks have been lately 
made in New York, with the base and pillars of a composi- 
tion which is silver-plated ; they are wonderfully light and 
beautiful, but there seem to be doubts as to their durability. 
More or less ornament can be displayed on the pillars and 
base of the tank, according to the taste of the owner, but it 
Seems as if simplicity and neatness were full as requisite 
here as elsewhere, and that the ornament of the tank should 
be the collection inside. As to the size of the tank, it very 
much depends on the place one has to put it in. se 
three sizes I have found from experience very useful i 
No. 1, Length, 18 in. ; depth, 103 in; width, 12 in. 
No. 2, Length, 24 in. ; depth, 14 in. ; width, 144 in- 
No. 3, Length, 28 in. ; depth, 134 in. ; width, 13 In- 
Number three is, perhaps, the best size of all, and it is by 
