TROPICAL AQUARIUM FISHES 217 
(The foregoing mixture of gasoline-paraffine will waterproof wood, 
concrete, brick, fabrics or anything that will absorb it. For fabrics to be 
used or bent, use only one ounce of paraffine.) 
After making one of these aquaria the knack becomes very easy. 
A row of them of uniform size presents a neat appearance and can be 
used in small space, since there is no projecting base. This style of con- 
struction is suitable for aquaria with bases up to eleven by eighteen inches. 
In larger sizes the uprights and top angles ought to be from five-eights to 
three-quarter inch metal, while heavy wire screen should be embedded in 
the cement for re-inforcement. 
If the frames are to be nickeled this should be done before pouring 
the cement base. 
Glass for Aquaria. Although double-thick window glass may be 
used for aquaria up to the 25 gallon size, plate-glass is so much hand- 
somer and costs s0 little more, it seems like a wise investment. If window- 
glass is used, the imported kinds will be found best. Plate-glass is now 
made in 3-16 inches thickness. This is suitable for aquaria under 50 gal- 
lons. For those for 50 to 75 gallons, the best thickness is 14 inch, and for 
the still larger sizes up to 120 gallons, 34 inch. The author and others 
have occasionally picked up bargains in plate-glass from plate-glass 
insurance concerns, who often have on their hands large remnants of 
bulk-windows. 
Setting the Glass. The edges of the glass should be carefully 
cleaned with whiting, ammonia or alcohol to remove any grease. It is well 
to first coat the edges which are to come into contact with the cement 
with gold size, allowing this to set for a day or two. This is more 
particularly needed with large plate-glass aquaria. Apply a liberal coating 
of aquarium cement to the inside of frame, and a thin but well covered 
coat to the contact edges of the glass. Press into place slowly but firmly, 
cleaning away at once all surplus cement. Light sticks cut of a length 
to brace across inside of aquarium will maintain an outward pressure 
on the glass for several days until it is fairly set. After the glass is well 
set it is advisable, especially with the larger sizes, to run a line of aqua- 
rium cement up the inside corners and along the bottom edges, covering 
with a narrow strip of glass, or, better, embedding a glass rod of from 
Y{ to 3-inch diameter in it, pressing in as far as possible and wiping 
away the surplus cement. 
Fill slowly in about a week and change water several times in two 
weeks before putting in fishes. 
Large aquaria nearly always leak a little at first, or after moving 
them, or even after emptying without moving. This usually corrects 
