
AQUARIUM CONSTRUCTION, TOOLS AND APPLIANCES 

gallons, and 3¢ 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, zinc white is 
more satisfactory and should be given the preference. 
CEMENTS FOR WoopeEN-FRAmED AguariA. 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 1 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, 1 part of litharge, 3 parts of 
Portland cement, 3 parts of fine sand and 1 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-FRAmMED AguariA. 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 ror Brass and IRon-Framep 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, 2 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 1 part by weight of zinc white, 1 part of red lead, 1 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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