104 CONSTRUCTION 



Bases. The best material for general use in aquarium bases is slate. 

 It is inexpensive, durable, easily worked, free from cleavage cracks, and 

 in every way reliable. The requirements for thickness are from ^-inch 

 for sizes up to 30 gallons, to 1% inches for 130 gallons. Polished Ten- 

 nessee marble makes a handsome and durable base. White marble is too 

 glaring and besides is easily chipped in moving an aquarium about. 

 Also when brought into contact with aquarium cement it absorbs and 

 spreads the oil, making a bad appearance. 



Aquarium bases usually extend from one to one and one-half inches 

 beyond the frames on all sides. Slate or marble bases ought to be 

 beveled sufficiently on the upper edges and corners to take away the 

 sharpness. The necessary holes through which the frame is to be bolted 

 can be drilled with an ordinary metal drill, but it costs very little extra 

 to have the slate-worker do this when he is finishing the base. The under 

 side of the hole should be countersunk with a larger drill to allow for 

 bolt nuts. Aquaria up to 10 gallons require 4 bolts, 20 gallons 6, and 

 for the larger sizes they should be placed about 10 inches apart. 



Frame Metals. Angle brass, iron or aluminum form the best metal 

 aquarium frames. For the amateur worker, brass offers the most advan- 

 tages. It is easily sawed, drilled and soldered, besides making a hand- 

 some appearance when polished and chromium or nickel-plated. II 

 nickeled it should be heavily plated. Angle iron is not so attractive in 

 appearance, but is undoubtedly more rigid. It cannot so well be soldered 

 Consequently the four corners of the upper and lower frames have to 

 be riveted through connecting elbow pieces on the inside or special castings 

 on the outside, and then the whole riveted to the uprights. Aluminum 

 has seldom been used, but makes an attractive frame. As the soldering 

 of this metal is of doubtful durability, it is safer to rivet the same as 

 with iron. 



For aquaria'up to 25 gallons ^-inch angle metal is suitable; up to 

 50 gallons, %-inch; up to 75 gallons, 1-inch; up to 125-gallons, 1^-inch. 

 The author prefers seeing as little of the frame as possible and for many 

 years has successfully used a 60-gallon aquarium constructed with only 

 ^-inch angle brass, but he would not care to make this as a general 

 recommendation. It is mentioned so that if others have the same idea 

 they will know that it is a mechanical possibility. 



Unless constructed of heavy angle iron, it is best to carry a light 

 rod across short dimension of the centre of top frame of aquaria over 

 30 inches in length, to prevent bulging by water pressure. 



Frame Construction. A hack-saw with fine teeth for metal working 

 will be needed to cut the proper lengths of angle metal. After carefully 

 determining proportions desired, cut the four uprights and then the 



