AQUARIUM CONSTRUCTION, TOOLS AND APPLIANCES 



gallons, and ^ inch for larger ones. Crystal plate is a beautifully polished, 

 white flint glass used for the finest aquaria. It is softer in composition 

 than the usual American plate glass. 



Aquarium Cements. The desired properties of an aquarium cement 

 are insolubility, resistance to the action of water, strong adhesion, and 

 absence of deleterious substances in its composition. It should "set," or 

 become fairly hard, but not too quickly, nor become so hard that it will 

 not permit of some expansion and contraction of the glass and frame. It 

 should be sufficiently soft to be readily applied and to adhere closely to 

 the surfaces. When its consistency is like that of stiff glazier's putty it 

 is sufficiently thinned for use. 



White and red leads form durable chemical combinations with linseed 

 oil, but the acid substances which accumulate in the aquarium produce 

 combinations with them which are injurious, so that when they are used 

 they should be covered with a coating of paste composed of whiting and of 

 shellac dissolved in naptha. Together with litharge, they may be used 

 where the glass is set into grooves; but for all purposes,^inc white is 

 more satisfactory and should be given the preference. 



Cements for Wooden-Framed Aquaria. For securing the glass 

 into wooden-framed aquaria, either of two cements may be used. One is 

 composed of 4 parts by weight of pitch and i part of gutta percha, boiled 

 together and applied warm to the heated frame and glass. The other 

 consists of 2 parts by weight of zinc white, i part of litharge, 3 parts of 

 Portland cement, 3 parts of fine sand and i part of powdered resin, kept 

 dry in an air-tight receptacle, and when used made into a thick paste with 

 boiled linseed oil. It "sets" quickly and becomes very hard. 



Cement for Zinc-Framed Aquaria. The glass and frame are 

 painted with "gold size" and permitted to dry. The cement is .composed 

 of equal parts of zinc white and red lead, rubbed into boiled linseed 

 oil, to which sufficient litharge is added to make a thick putty. 



Cement for Brass and Iron-Framed Aquaria. A good cement 

 for aquaria of thin glass, but not so well adapted for double-thick or plate 

 glass, consists of 3 parts by weight of zinc white, 1 parts of litharge and 

 2 parts of Portland cement, mixed into a thick paste with boiled linseed 

 oil, and an equal bulk of glazier's putty added. This "sets" hard and 

 makes a very durable cement. For plate glass the following are extensively 

 used: First, the frame, base and glass are painted with gold size. The 

 cement is made of i part by weight of zinc white, i part of red lead, i part 

 of litharge, 16 parts of glazier's putty and a very little ivory black, well 

 kneaded together with a little boiled linseed oil and a small quantity of 

 Japan drier. This "sets" slowly and never becomes perfectly hard, so as 



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