Q. Why will a chimney smoke if it needs sweeping?
A. Because the obstruction in the chimney (presented by the loose soot, to the free passage of the smoke) delays its current, and prevents the draught.
Q. Why will a chimney smoke, if out of repair?
A. 1st—Because the loose mortar and bricks obstruct the smoke: and
2ndly—The cold air (oozing through the chinks) chills the air in the chimney, and prevents its ascent.
Q. Why will an arnott’s stove smoke, if the joints of the flue do not fit air-tight?
A. Because the cold air (which gets through the joints) chills the air in the flue, and prevents its ascent.
Q. Why does an old fashioned farm chimney-place so often smoke?
A. Because the opening is so very large, that much of the air which goes up the chimney, has never passed near the fire; and this cold air mixing with the other, so reduces its temperature, that it ascends very slowly, and the draught is destroyed.