THE FRESH-WATER AQUARIUM. 17 
structed vessel is not at hand; and even as adjuncts to 
high-class tanks, such vessels are frequently necessary 
and have special uses of their own. Still the tank, 
whether rectangular or vase-shaped, is a distinct thing in 
itself. The beauty is to be found it its completeness and 
the extent afforded for a variety of objects; and when we 
speak of an aquarium, we mean a vessel holding at least 
eight to thirty or more gallons of water, formed partially 
or wholly of glass, and stocked with plants and fishes in a 
living and healthy state. A glass lid is essential to pre- 
vent the entrance of dust and escape of any of the inha- 
bitants. Fishes will sometimes leap out, and reptiles crawl 
out ; and without a lid, some pretty objects may be lost. 
CHAPTER III. 
FITTING UP. 
Rockwork claims the first consideration when we pro- 
ceed to fit up and furnish a tank. For a fresh-water 
aquarium, I do not recommend rockwork of any kind ; 
and in the case of a vase, rockwork is positively dangerous, 
from its weight, and, unless very skilfully managed, will 
be ugly rather than ornamental. In the marine tank 
a few pieces of rock add to the beauty of the scene and 
the comfort of the creatures. 
In fitting rockwork, some amount of taste and judgment 
must be brought into exercise. Shells and filagree work 
are largely used by some folks; but they belong properly 
to the child’s aquarium—they suggest dolls and battle- 
dores. Some rough fragments of any kind of non-metallic 
Cc 
