A. Because the air is colder in winter, than in summer-time.
Q. How does the coldness of the air increase the heat of a fire?
A. For two reasons: 1st—Because cold air being more condensed than hot air, contains a greater body: and
2ndly—Cold air rushes more quickly to the fire, and supplies more oxygen.
Q. Why does the sun, shining on a fire, make it dull, and often put it out?
A. 1st—When the sun shines, the air is rarefied; and, therefore, flows more slowly to the fire.
2ndly—As the air is rarefied, even that which reaches the fire, affords less nourishment.
Q. Why does the air flow to the fire more tardily for being rarefied?
A. The greater the contrast (between the external air, and that which has been heated by the fire) the more rapid will be the current of air towards that fire.
Q. Why does rarefied air afford less nourishment to fire, than cold air?