THE CABINET AQTTAEIUM. 29 



board in the place cut for it (A A). See that it is quite 

 upright. Use small French nails, and hammer them well 

 into the zinc. One nail at each side of the moulding ■will be 

 sufficient. 



, Nail the piece of zinc, which has been cut IJin. wide, quite 

 round the edge of the wood for the bottom. The zinc to the 

 height of Jin. should come above the board. The nails ought 

 to be put through the centre of the zinc. If the tank is not 

 more than 6in. long, three French nails in each side will be 

 enough; one nail at each end, close to the edge of the 

 uprights, and one in the middle. 



Window-glass should now 'be cut to fit the frame just m.ade, 

 and put in its place (0 C). The glass ought to just reach 

 the holes in the zinc made for the wire. 



Draw foiu" pieces of thin copper or brass wire tightly 

 through the holes made for it, and fasten it neatly (D). 

 Copper wu"e must be well stretched before it is used. The 

 wire should then hold the glass sides in their places. 



Melt in a tin saucer over a lamp four parts pitch and one 

 part gutta-percha. The pitch and gutta-percha must be well 

 mixed before it is fit for use. It should boil for some little 

 time and be stirred with a small iron spoon. Instead of the. 

 pitch and gutta-percha the following cement may be used, viz. : 

 One part pitch, one part resin, and a little boiled oil — ^this last 

 in the proportion of a tablespoonful to ^Ib. pitch. This also 

 must be boUed and well mixed together. 



Take what is already made of the aquarium and hold it in 

 the left hand. In the right hand take a spoonful of the 

 boiling cement and allow it to cool a little for a moment or 

 two, or it will crack the glass. Then put the spoonful of 

 cement into one comer of the aquarium, and having returned 

 the spoon to the saucer, with both hands tUt the aquarium 

 carefully, so that the cement will run just at the junction of 

 two pieces of glass, up to the top of the aquarium and 

 then down again. Continue to do this until the cement ceases 

 to flow. If this be well done, the cement will not be seen 

 beyond the edges of the moulding. Treat aU the comers 

 in the same way, but do not begin a second comer until the 



