THE CABINET AQUARIUM. 31 



vessel is made entirely of glass, of which there are five pieces, 

 fastened together with marine glue. The two sides and the ends 

 are stuck to the bottom at the distance of about ^in. from its 

 edge all round. The former are iin. shorter than the bottom, 

 and the latter are nearly if not quite as broad. The sides are 

 put in their places first, and when they are finn the ends are 

 glued to the extremities of the sides. The gluing is done by 

 holding a piece of glue about the size of a pea, attached to the 

 point of an awl, in the flame of a candle until it begins to bum 

 and melt, when it should be gently drawn along a mark which 

 has been made on the glass until the glue at the end of the awl 

 is used. The glue should be placed on the glass quite evenly 

 to the depth of about |-in., and the same in breadth. When 

 a line of glue is completed, the edge of the piece of glass 

 which is to be fastened by it should be gently heated, and 

 then pressed carefully into the glue. In a minute or two the 

 glass will be quite firm. The gluing should be executed 

 neatly, for any trimming that is required to be done after the 

 aquarium has been put together, tends to weaken it. As soon 

 as the little tank is finished, it may be filled with water, and if 

 the work has been done with care there will be no leaking. 

 Should the vessel, however, be not quite watertight, it may 

 be easily made so by an additional piece of glue, or by 

 running a little of the pitch-cement previously recommended 

 over the weak spot, and, to make matters safer, over every 

 joint. Such an aquarium as the one just described is very 

 useful for small aquatic animals ; but it should not be con- 

 structed of greater dimensions than the following, viz., 9in. 

 long, 2in. wide, and 2Ln. deep. I have made tanks of this 

 kind as large as 1ft. long, 6in. deep, and 6in. wide; but 

 I find that they are liable to give a little when the weather 

 or the room in which they are placed is too hot. Though 

 the joints open sometimes under these circumstances as much 

 as ^in., the glue and pitch together become so elastic that the 

 water is rarely allowed to escape. 



The large bottles, which have been already referred to as 

 suitable for the cabinet aquarium, can be cut in half by satu- 

 rating a piece of thick worsted in paraflBu, and tying it evenly 



