14 THE FRESH-WATER AQUARIUM. 
able in some districts; and if the two ends and bottom 
were formed of such a material, and buttressed together 
by means of a rude arch, the fire would unite the whole, 
and render it as hard as stone. Mr. Dodgson, of Wigton, 
states, through Mr. Gosse’s pages, that he has formed two 
tanks of this kind of clay: they measure three feet long 
by thirty inches broad and high, holding thirty gallons 
each. The weight being very enormous, the cost of car- 
riage is so serious a matter that such tanks can only be 
had in the neighbourhood of a pottery. In London, the 
substitute for the clay would be terra cotta. 
Mr. Warington’s Tank is of a peculiar construction, 
and is intended to admit the light from above only, and 
also to enable the water to absorb atmospheric air freely. 
Mr. Warington says :—‘‘ After five years’ and upwards 
experience, I have now adopted an aquarium, the form of 
which consists in a four-sided vessel, having the back 
gradually sloping upwards from the bottom at an angle of 
fifty degrees. The chief peculiarity of this tank is, that 
it admits light at the top only; the back and sides are 
usually composed of slate.” 
Bell Glasses, or vases, are now Largély used for aquaria. 
Mr. Hall, of the City Road, was the first who thought of 
turning a propagating glass upside down to extemporise an 
aquarium; but he surely never thought that in a few 
months the aquarium would gain thousands of new fol- 
lowers through that simple trick of his in creating a cheap 
and elegant tank. Bell glasses for aquaria are to be 
obtained of any of the dealers in aquarian stock, and at 
most horticultural glass warehouses. The sizes range 
