484 AMERICAN ANGLER'S BOOK. 



The best shape is one of four sides. In a round vessel the 

 proportions of the fish are distorted, when seen through the 

 convex sides, as any person has observed in looking at Gold- 

 fish in a glass globe. 



Wood is an objectionable material for the bottom of an 

 Aquarium, on account of its liability to warp. Soapstone can 

 be used, but cast-iron is the most suitable. No fear need be 

 entertained on account of its liability to contract with cold 

 or expand with heat, as the water in the tank will serve to 

 maintain an uniformity of temperature between the glass 

 sides and iron bottom. For the same reason the frame (the 

 four posts at the corners and the rim around the top of the 

 glass), should also be of iron. The plate glass forming the 

 sides and ends should fit neatly into grooves in the bottom 

 and frame, and should be cemented with some composition 

 which does not contain any ingredient that will affect the health 

 of the fish. The tank should be filled with water and let 

 stand for a few days, to see that it is perfectly water tight 

 before putting the fish into it. 



If placed at a window with a southern exposure, the 

 growth of the plants is accelerated ; though in such situa- 

 tion care should be used to lower the shade of the window, 

 if the sun shines for any great length of time on the tank. 



Clean white gravel has been found to be the best bottom, 

 as it can be removed whenever it becomes necessary, and 

 returned after washing. The ornamental rockwork, such as 

 arches, grottos, &c., can be arranged according to one's own 

 taste. 



Plants for the Aquarium. — Suitable aquatic plants can 

 be procured in almost any running water or mill-pond in the 

 vicinity of the city. The ditches into which the water from 

 the Delaware and Schuylkill flow through sluices, and where 



