CONSTRUCTION 107 



The modern electric soldering iron is a very convenient tool, but 

 the author has managed very well with only an automatic alcohol blow 

 torch. Before soldering, the surface is properly prepared by scraping and 

 the application of a flux composed of hydrochloric acid which has dis- 

 solved as much zinc as possible. Very good flux pastes are obtainable in 

 hardware stores. When the heat is applied and the liquid of the flux has 

 boiled away, touch the heated surface occasionally with soft solder wire. 

 Apply a little more heat after first sign of melting, withdraw flame and 

 proceed to quickly solder. Where work is in a position so that it is diffi- 

 cult to hold the pieces steadily in place while solder cools, an assistant 

 can instantly "set" it by pouring on a little water. Small "C" clamps 

 are most useful while soldering to hold uprights and side frames together. 

 They may be obtained for twenty-five cents or less. If acid flux darkens 

 the hands, the stain can be removed by diluted ammonia water. 



Small Aquaria. Compact, neat and substantial aquaria can be made, 

 but without projecting base— in fact, without slate at all. The bottom 

 is self-contained concrete. The top frame and upright corner posts are 

 of J^-inch angle brass, and the bottom frame of 1-inch size. In the 

 inside edges of bottom are soldered a few brass screws. Now prepare a 

 mixture of one part of Portland Cement to two of clean sand, brought to 

 a thick, mushy consistency by addition of water. Lay the frame on glass 

 and pour in the cement to a depth of Y± inch, seeing that it lies smooth, 

 particularly at edges where the aquarium glass is to rest. 



After the cement is poured and smoothed, it should be covered and 

 allowed to dry slowly. In about two days the frame and base can be slid 

 off the glass. The screws soldered on inside will always bind the concrete 

 base securely in place. To prevent free chemicals washing out of cement 

 into the aquarium water, it is well to waterproof the inside of base before 

 setting glass in. This may be done by melting, under a blow-torch, chips 

 of paraffine on the concrete. 



Frames should be plated before pouring the cement base. 



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 a small space, since there is no projecting base. This style of 

 construction is suitable for aquaria with bases up to 11 by 18 inches. 



Wired ribbed glass or slate bases may be used instead of Portland 

 Cement, and are recommended for larger sizes. 



Glass for Aquaria. Although double-thick window glass may be 

 used for aquaria up to the 25-gallon size, plate-glass is so much handsomer 

 and costs so 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 inch thickness. This is suitable for aquaria under SO gallons. 



