44 
THE ART OF REARING 
3. Of the Hot-house or Room in which the Silk- 
worm should be hatched . 
The first use of the thermometer should be in 
the hot-house which is destined for the hatching 
of the eggs. 
The eggs of these insects are not hatched by 
means of animal heat, but by the uniform atmo- 
spheric warmth, which should surround them en- 
tirely. 
As it may be more favourable to our interests 
that the silk-worm should be developed whenever 
we find it convenient ; and as this insect must be 
reared in a season, which, in our climates, has not 
the requisite warmth, it is therefore indispensable 
to create an artificial temperature suited to its 
progress. 
A small room or space should be preferred to 
a large one, as it is thus more easy to regulate 
the heat, and as it also saves fuel. 
The small ajDartment in which l reared silk- 
worms, was about twelve feet square, and ca- 
pable of commodiously hatching, not only ten, 
twenty, or thirty ounces of the eggs, but even 
two hundred if required. This small apartment 
must be particularly dry. 
diem toM. Lagarde, optician at Paris, who lias manufactured 
some on a similar principle ; they may be had of him, Quai 
de Gevres, No. 10, Third Story, Paris. He also makes 
the thermometrograplie, which I mentioned in the preceding 
note . — Note of the Translator. 
