MINIATURE GREENHOUSES. 
105 
purchased four panes of ordinary window glass, which cost 
me one dollar. Two of these panes were 12x16 and two 
16x26. I got a carpenter to make a substantial walnut 
frame, with an oaken bottom and furnished with small 
grooves for the glass, which I inserted, and cemented with 
the following preparation that cost just forty cents. One 
part (by measure) of litharge, one part plaster of Paris, one 
part fine beach sand, one third part of finely powdered 
resin. Mix well, and make into a putty with good boiled 
linseed oil. It will stand water at once.” 
Handsome tanks are made of iron, with the glass fitted 
in at the sides ; but, whatever the outside may be, the first 
process for the inside is to spread an inch of clean, coarse 
gravel, with all the sand washed out of it, over the bottom. 
It should then be filled within an inch or two of the top 
with clean rain or river water, and plants are required to 
keep this water pure and clean. They may be of any kind 
that grows quite under the water, although the calla lily 
often does well in an aquarium, and is very ornamental. 
Tape-grass and eel-grass are very commonly used. The 
plants must be pulled very carefully from their native bed, 
and washed perfectly clean ; they are then sunk by means of 
a small stone tied to the root, and this is all the planting 
they require. 
Before the animals are put in, it is advisable to shade 
the aquarium for two or three days that the plants may 
become firmly established. Very few fish in proportion to 
the size of the tank should be introduced, as they require 
more oxygen than the small water animals, and overcrowd¬ 
ing produces very serious effects. But lizards, snails, newts, 
etc., are needed to keep the water clear. A somewhat 
shaded position is better for the aquarium than a bright 
light. 
The greenhouse proper is a structure outside of the 
house, or a building partly of glass standing by itself. A 
