HOW TO COLLECT, AND STOCK THE TANK. 169 



fully constructed Aquariums of large dimensions are 

 apt to occasion much trouble, especially if shifted 

 often when full of water. 



In addition to several primitive tanks, consisting 

 of a china sugar-basin, two glass tumblers, &c., I have 

 two others, the largest of which measures fifteen 

 inches in diameter by six inches in depth, and cost 

 me just four shillings. It rests on a mahogany base 

 supported by ball feet, and presents, I believe, rather 

 a pleasing effect, standing on a small table near the 

 window. 



Some persons object to the circular tank, on the 

 ground that its occupants, when seen from the sides, 

 appear magnified. This fact is rather a recommenda- 

 tion with me, as it presents more distinct views of 

 each movement in the vessel; and whenever I wish to 

 see the objects at their natural size, I can do so by 

 looking in from the top. 



On the edge of the tank are placed three corks, 

 notched out to the thickness of the glass ; on these 

 there is placed a circular piece of common glass, cut 

 two inches larger than the diameter of the tank. As 

 the corks are about three quarters of an inch above 

 the tank, they allow a current of air to pass over the 

 water, and also prevent, to a certain extent, particles 

 of dust from falling in. On the edge of the moveable 

 lid I paste a stripe of white paper, binding like, which 

 prevents the glass from cutting the hand of any per- 

 son moving it about. 



I employ a glass syringe to aerate the water occa- 



