114 SEA-WATER AQUARIA. 



are as follows : — Height, i foot 3^ inches (exclusive of slate rim) ; 

 breadth, i foot 6J inches ; length, 2 feet 5| inches. It is placed 

 on an exceedingly strong wooden sfa?id (i), 2 feet 5 inches high. 



Both the tank and stand were obtained from Messrs. Dick 

 Radcliffe and Co., of 128 and 129 High Holborn, London. 



The cover of the tank (4) at first consisted of a central piece of 

 glass, supported by a perforated and painted metallic framework. 

 This, however, was soon found to be extremely unsatisfactory, as 

 the paint chipped off, the metal corroded, bits fell into the water, 

 and the animals suffered in consequence. With a fountain playing 

 and the metal frame being continually wet by the spray, it can be 

 readily understood how the water became fouled. So 1 had an 

 entirely new cover (4) made by the Indiarubber, Gutta Percha, 

 and Telegraph Works Co., Limited, of 54 Castle St., Liverpool. 

 This consists of five pieces of glass, fitted into a framework of 

 ebonite. The central piece of glass is over 6 inches broad, 

 rather more than 12 inches long, and 7^ inches above the level of 

 the top of the tank, the other four pieces of glass sloping up to it. 



The main portion of the rockivoi'k in the tank consists of a 

 porous substance called Tufa ; but other parts are constructed of 

 slag, pumice, etc., fixed in cement, and in addition there are 

 stones, shells, gravel, and, at one end of the tank, sand to the 

 depth of 3 J inches. 1 should mention that the sand was obtained 

 from the sea-shore. 



In one of the slate ends of the tank there are two circular 

 holes, half-an-inch in diameter, both in the middle line, one being 

 13 inches, the other yj inches from the base. I made these holes 

 with an auger or centre-bit, which bored through the slate without 

 any difficulty and without cracking it. I then got two corks to fit 

 the holes and pierced each with a "cork-borer," so that a glass 

 tube of one-third of an inch in diameter could be pushed through. 

 One of the corks, through which I had pushed a short piece of 

 glass tubing, I fitted tightly into the lower hole in the slate ; and 

 to the outer end of the glass I secured a piece of indiarubber 

 tubing, which runs into a large dark reservoir. This forms the 

 overflow tube {11), so that the water in the tank remains at the 

 level of 7J inches. 



Into the uppermost hole in the slate another cork is fixed. 



