218 GOLDFISH VAEIETIES Al^D 



itself within a few days, but, as elsewhere directed, it can nearly always 

 be stopped by making the water very mnddy. The particles of dirt get 

 into the leak and choke it up. 



Aquarium Cements. The prime requisites of an aquarium cement 

 are resistence to water, adhesiveness, moderately quick setting without 

 ever becoming stone-hard, and being non-poisonous. A cement com- 

 bining these qualities is composed of one pound of litharge, one pound of 

 Plaster of Paris, two ounces of powdered resin and one-half pound of 

 glazier's sand ; mixed with boiled linseed oil to a consistency of putty suit- 

 able for glazing. This cement has been found to be good for both fresh 

 and marine water aquaria. A durable cement for those who cannot 

 obtain very fine sand is made of equal parts by weight of zinc white, 

 whiting and litharge, mixed with boiled linseed oil to a firm but tacky 

 consistency. 



Cement for Marine Aquaria. A cement used for large, city 

 marine aquaria is composed of 3 parts by measurement of Portland 

 Cement, 3 parts fine white sand, 1 part powdered resin ; mixed with 

 boiled linseed oil. 



Cement for Wooden-Framed Aquaria. The best cement for 

 small wooden-framed aquaria is made of 1 part of gutta percha and 4 

 parts of pitch, boiled together and applied warm, first heating the glass 

 somewhat. It is difficult to handle this quickly enough on large aquaria, 

 for which the following will be found better: 3 parts Portland Cement, 

 2 parts zinc white, 3 parts fine sand, 1 part powdered resin, made into a 

 firm paste with boiled linseed oil. 



CONCRETE AQUARIA 



The making of concrete aquaria opens a new and an unlimited field. 

 Those who have felt that the metal-frame aquarium is hopelessly restricted 

 and commonplace can here find more room for individual expression, 

 design and achievement. The illustration facing title page gives an idea of 

 possibilities along this line. The aquarium shown is one designed and 

 built by Mr. L. M. Dorsey and probably represents the highest develop- 

 ment, up to this time, of artistic ideas as applied to a household aquarium. 

 In the Philadelphia Aquarium Society annual competition Mr. Dorsey 

 was awarded the prize cup three times, thereby becoming its permanent 

 possessor. 



As individual ideas will vary so widely in the design of concrete 

 aquaria, only a few (yet important) directions can be given. Cement 

 should be of the highest grade, fresh and free from lumps. A mixture 

 of one part cement to two of clean, sharp sand is about right. Wooden 



