rarefraction

Updated: May 26, 2025

As the smoke and vapour rise in consequence of their being rarefied by heat, and made lighter than the air of the surrounding atmosphere, and as the degree of their rarefraction is in proportion to the intensity of their heat, and as this heat is greater near the fire than at a distance from it, it is clear, that the nearer the throat of a chimney is to the fire, the stronger will be what is commonly called its draught, and the less danger there will be of its smoking, or of dust coming into the room when the fire is stirred.

Mary Eaton - The Cook and Housekeeper's Complete and Universal Dictionary; Including a System of Modern Cookery, in all Its Various Branches, Adapted to the Use of Private Families