THE SILKWORM. 



be dry and airy and possess a good space of window and a fire- 

 place. The windows should be provided with calico blinds. 

 Ton will also want a small portable stove to light in very 

 cold weather and to keep the room dry. Shelves should run 

 all round the room, one over the other, at the distance of 

 twenty-two inches jfrom each other. These shelves may be 

 merely frames, on which coarse netting may be strained, oi 

 wicker-work, or of any material through which air can pass ; 

 over the net must be laid sheets of thick paper, or lengths of 

 cheap cloth or calico. The best width for the frame-shelves is 

 about two feet two inches ; but they may be of any width, 

 according to the size of the room. The netted frames on which 

 the worms are fed should be made to slide into a groove for 

 the greater convenience of feeding the upper and lower tiers. 

 As it is necessary that a steady temperature should be main- 

 tained, a thermometer is needful — ^two thermometers indeed; for 

 it will happen sometimes that one part of a room will be several 

 degrees colder than another. 



A plate of salt, or, if you would like to dignify the humble 

 apparatus, you may call it a " hygrometer," is a tolerable 

 substitute for a thermometer. When the hygrometer indicates 

 a very damp state of the atmosphere, or when the salt appears 

 very damp, wood-shavings should be burnt, or straw in the 

 fireplace to absorb the humidity, and replace it by the external 

 air, which is dried by this same blaze. I say blaze, and not 

 fire, for two reasons : the first is, that with two pounds of 

 shavings or of dry straw there can be attracted from aU points 

 towards the chimney a large body of air, which issues at the 

 flue of the chimney ; while in the mean time, this air is replaced 

 by a similar quantity of exterior air, which spreads over the wicker 

 hurdles or network, and revives the exhausted silkworms. 

 This change of air may take place without efiecting any material 

 variation in the degree of heat in the room. If, on the contrary, 

 thick wood were employed, it would require more time to move 

 the interior air, ten times more fuel might be consumed, and the 

 room would be too much heated. The motion of air is, all 

 circumstances being equal, proportionate to the quantity 

 of blaze of the substances that bum quickly. When wood- 

 shavings or dry straw cannot be gbt, small sticks and light 

 wood may answer. 



As soon as the flame rises, the salt shows that the air has 

 become drier, and the degrees of it can be seen distinctly. 

 During the hatching of the eggs, the temperature of the cham- 



