10 



FRESH-WATEB AQUABIA. 



block will be useful, and all of them are more or less necessary, 

 not only for tlie preparation of the zinc framework of this 

 particular aquarium, but also for other aquaria of a much 

 easier make. The zinc should be moderately stout — that is, 

 about No. 12 gauge. 



Having decided upon the dimensions of the tank now about 

 to be made, cut four strips of zinc its exact length, four its 



Fig. 14. Iron-faced Block. 

 A, Side View ; B, End View ; C, Face View. 



exact breadth, and four its exact height. Each piece ought 

 to be 25in. wide. Now take a strip of zinc, mark a line down 

 its centre, and place it upon the iron block (Fig. 10), the line 

 marked on the zinc being exactly over the middle of the groove 

 and running lengthwise with it. Then take the steel bar 

 (Fig. 11) by the handle in the left hand, hold the rod part 

 of it exactly over the line marked on the zinc (and which, of 



v/ 



Fig. 15. 



FIG. 16. 



course, will be over the centre of the groove in the block), and, 

 with the hammer in the right hand, drive the bar and the zinc 

 home into the groove, and about 6in. of the strip of zinc will 

 be bent into the shape of Fig. 15 ; bend the rest of the strip 

 in this way, then press, by means of a pair of pincers (Fig. 16), 

 the zinc tightly round the steel bar. When this has been done 

 evenly and carefully along the whole length of the strip, put 



