174 THE SEA-SIDE AND AQUARIUM. 



dinary traveller. Very few, indeed, would have the 

 least idea of the kind of luggage that your carpet bag 

 contained. 



Sea water can always be readily enough obtained. 

 A stone jar should be kept for the purpose of holding 

 it. Care must be taken that the jar is perfectly free 

 from any smell, as that of spirits, dirty cork, or the like ; 

 any such impurities would instantly spoil the supply. 

 One great point in favour of an Aquarium, and one by 

 no means generally understood, is, that having once 

 filled the tank with the briny fluid, it will last for 

 months, and even years, if proper care be taken, 

 without requiring one particle of sea water to be again 

 added ; for as the water evaporates, the salt falls to 

 the bottom, and the deficiency may be supplied 

 with fresh water from the cistern or filter. In order 

 to ascertain when the sea water is of the proper den- 

 sity, you require to have a gravity bubble, which can 

 be had for sixpence. This may always be kept in 

 the tank. When " all's well " it sinks to the bot- 

 tom, and when anything comes amiss it rises to the 

 surface, but falls again quickly upon the introduction 

 of the fresh water. 



A more simple plan is to mark on the glass the 

 height of the fluid when the tank is first filled ; then, 

 as the water sinks, raise it to the original level by 

 means of the fresh water. 



The arrangement of the " stock " of an Aquarium 

 is quite a matter of taste j perhaps no two persons 

 adopt precisely the same plan. It may, therefore, be 



