THE STUDENT'S AQUARIUM. 



13 



built for rock work, again your ideas may vastly improve this 

 methodical way of doing. Of course the pumice stone can be 

 joined together with the same mixture of Portland cement and 

 sand. One of the prettiest home aquariums I ever saw repre- 

 sented a small cave, with pumice stone hanging as stalactites 

 from the top. They were hung in rows and were arranged on 

 strips of wood running from end to end of the tank ; in front 

 they just touched the water, and gradually lengthened with 

 each row, until at the back they nearly touched the bottom of 

 the tank. The effect was really beautiful. In filling the tank, 

 as we do not wish to disturb the gravel, sand, &c, we put a 

 pail of water so that its bottom is as high as the top of the tank ; 

 we then get a piece of rubber pipe, say about three feet long, 

 close one end by bending over about three inches, and fill the 

 pipe with water to about three inches of the other end, and 

 close it in same manner, place one end in the pail of water and 

 the other end in the tank below the bottom of the pail, then 

 release both ends and thus create a siphon. The tank is emp- 

 tied in same manner, but of course the pail into which you wish 

 to empty the water must be below the tank. Everybody lives 

 in the neighborhood of a lake or large pond of fresh water, and 

 we will now go on an expedition to collect some plants, for 

 aerating the water. We want something to drag the bottom of 

 the lake with, — a garden rake is a good thing for the purpose ; 

 tie a good stout cord to the handle of it, then find what looks 

 like a clear spot along the edge of the pond or lake, and is not 

 too deep ; throw the rake in and drag it along for a short dis- 

 tance, and if you do not get any green plant the first time, no 

 matter what the season of the year, try till you do, as it is there. 

 You will likely pull it out some 2 or 3 feet long ; nip the ends 

 off about 6 inches or even 2 inches from the top ; these top 

 ends are what you want, but as it grows from a joint it will not 

 matter what part you take so long as it is green. For the 

 Fresh-water Aquarium I will not recommend any one variety. 



