Accessories. 



67 



and that if broken it can be repaired. The ordinary 

 commercial glass troughs unfortunately do not meet these 

 requirements. They are difficult to clean, they are in- 

 variably hard to mend when broken, and they very often 



FIG. 26. Botterill's Trough. 



leak when water is put in. The one that we have found 

 most serviceable is the Botterill's trough, as shown in Fig. 

 26, which consists of two vulcanite plates, between which 



FIG. 27. Eousselet's Live-cage. 



are placed slips of glass, having between them an india- 

 rubber band, small bolts and screws passing through the lot 

 to hold them together. This is not an ideal trough, but it 

 certainly answers its purpose as well as any at present made. 



