A pleasant adjunct to a window-garden, living room, or conservatory, is a large glass globe or glass box containing water, in which plants and animals are living and growing. A solid glass tank or globe is better than a box with glass sides, because it does not leak, but the box must be used if one wants a large aquarium. For most persons it is better to buy the aquarium box than to attempt to make it. Five points are important in making and keeping an aquarium: (1) The equilibrium between plant and animal life must be secured and maintained; (2) the aquarium must be open on top to the air or well ventilated; (3) the temperature should be kept between 40° and 50° for ordinary animals and plants (do not place in full sun in a hot window); (4) it is well to choose such animals for the aquarium as are adapted to life in still water; (5) the water must be kept fresh, either by the proper balance of plant and animal life or by changing the water frequently, or by both.

The aquatic plants of the neighborhood may be kept in the aquarium, - such things as myriophyllums, charas, eel-grass, duckmeats or lemnas, cabomba or fish grass, arrow-leafs or Sagittaria, and the like; also the parrot's feather, to be bought of florists (a species of myriophyllum). Of animals, there are fishes (particularly minnows), water insects, tadpoles, clams, snails. If the proper balance is maintained between plant and animal life, it will not be necessary to change the water so frequently.