Q. Why do some chimneys smoke?
A. If fresh air is not admitted into a room, as fast as it is consumed by the fire, a current of air will rush down the chimney to supply the deficiency, and bring the smoke along with it.
Q. What prevents air being supplied, as fast as it is consumed by the fire?
A. Leather and curtains round the doors; sand-bags at the threshhold and on the window-frames; and other contrivances to keep out the draught.
Q. Why is it needful for cold fresh air to be so constantly supplied?
A. If water be taken with a pail out of a river, other water will rush towards the hole, as soon as the pail is lifted out; and if air be taken from a room, (as it is, when some of it goes up the chimney) other air will rush towards the void to fill it up.
Q. Why will it come down the chimney?
A. Because if doors and windows are all made air-tight, it can get to the room in no other way.
Q. What is the best remedy in such a case?