3706 The Zoologist — October, 1873. 



wood, turned into pillars, each surmounted by a knob, and united by a 

 frame top going all round. The glass is set in grooves in the slate and 

 wood, and fastened with white-lead putty." — 'Aquarium,'' p. 101. 



Mr. Warington, after experimenting unsuccessfully for some 

 years, gave instruction for the making of a small tank as a more 

 permanent reservoir, with certain improved naodifications as regards 

 form and the admission of light. He writes thus : — 



" From the experience I had obtained in my experiments with the fresh- 

 water tank, I was induced to modify slightly the construction of the vessel ; 

 thus at the back or part towards the light the framing was filled with slate, 

 in the same way as the ends and bottom ; for I had found that the glass 

 originally employed very soon became covered with a confervoid growth 

 which had an unpleasing appearance to the eye, and in consequence of 

 which I have been obliged to paint the glass on tlie exterior to prevent the 

 growth from increasing to too great an extent. It was almost an unnatural 

 mode of illumination, as all the light should pass through the surface of the 

 water. The front towards the room and the observer was constructed of 

 plate-glass, the whole being set in a stout frame-work of zinc and cemented 

 with what is known under the name of Scott's cement, and which I have 

 found to answer for the purpose most admirably. Within the tank were 

 arranged several large pieces of rockwork thrown into an arched form, and 

 other fragments were cemented against the slate at the back and ends, 

 and at parts along the water-line, so that the creatures could hide them- 

 selves at pleasure ; a short beach of pebbles was also constructed in order 

 that shallow water could be resorted to if desired; the whole tank was 

 covered with a light glass shade to keep out the dust and retard evaporation." 

 —'Zoologist; 4119. 



Professor Ryraer Jones, modestly referring to Mr. Warington 

 and Mr. Gosse as his authorities, recapitulates Mr. Wariuglon's 

 instruction, and points out its advantages : — 



" First, that it allows of a most extended view of the whole interior of the 

 aquarium. \ 



" Secondly, that it enables the occupants to resort to any depth they may 

 desire, or even to ascend the sloping back and emerge from the water. 



" Thirdly, it admits of a much larger surface being exposed to the action 

 of light; and 



" Fourthly, the sloping top allows the water which condenses on the 

 glass to trickle off and return to the aquarium without first resting on the 

 zinc or iron frame-work. It need hardly be suggested that the sloping back 

 is to be covered with light rockwork extending to a short distance above the 

 water line." — ' The Aquarian Naturalist,' p. 6. 



