310 
THE ART OF REARING 
between the egg and the cloth, aslant, and thus 
a quantity may be scraped in a short time. 
(Fig. 3.) 
The Thermometer. — I have described it and 
its uses in a separate paragraph. (Chap. IV. 
§2.) 
The Stove. — It is intended to warm the labo- 
ratory. It heats much better when constructed 
on the principle of receiving external air, heat- 
ing it, and then dispersing it in the laboratory. 
The rarefied air when it comes in hot, is a purifier, 
as it expels the interior air. If required, the 
holes or apertures through which the rarified air 
passes may be stopped up, when there is fire in 
the stove. These apertures may be used as ven- 
tilators, to admit cold air, when there is no fire 
in the stove. (Fig. 5.) 
Small Boxes or Trays for Hatching the Eggs 
of the Silk-worms. — There should be some of all 
sizes, that each ounce of eggs may have a space of 
seven inches and four lines square. They should 
be made of thick pasteboard, if they are small ; 
and if larger, and intended to hold ten or eleven 
ounces of eggs, of thin board. They should be 
numbered with very visible ciphers marked on 
the sides. (Fig. 6.) 
Hurdles , or Trays, or Table-stands. — They 
are used covered with paper, to hold the worms ; 
mine have the surface made of cane. They may 
