Two Notes on Jane Austen 219 front to back of the fireplace, so that they reflected the heat into the room. But the most important change, as shown by Count Rumford's Essay "Of Chimney Fireplaces" in his Essays, Political, Economical, and Philosophical I, 303 (Boston, 1798), was the narrowing of the throat of the chimney as he called it, that is the opening between fireplace and chimney proper. This was done by building a false back in the very deep fireplaces of the time, thus bringing the fire forward and hence nearer those to be warmed. The false back was carried up above the fireplace some two-thirds of a foot, and according to Count Rumford's plans left the long narrow opening into the chimney only four inches from front to back. All the changes improved the draft, corrected smoking, and conserved a large percentage of heat. Franklin had still further conserved heat by his Franklin stove, virtually a sheet-iron fireplace set out somewhat into the room. Count Rumford superintended the modifying of many fireplaces in the homes of wealthy people in England, as shown by his own references in his Essays, and by occasional allusions in other places. Thus Maria Josepha Holroyd, daughter of Lord Sheffield the friend of Gibbon and afterwards Lady Stan- ley, alludes to him in one of her sprightly letters: Friday Count Rumford came, and has been turning all the Chimneys and Fireplaces in the House topsy turvy ever since, till this morning when he took his departure. Have you by any Chance seen his Essays which are lately pub- lished? I dare say you have not forgotten him as Sir Benjamin Thompson 13 years ago, and that you remember he was an uncommon Genius and very pleasant Man. . . . What raises him even more than his Talents in my mind is his really philanthropic benevolent motives, that urge him to attempt doing all the good he has done. 1 It is not strange, therefore, that Jane Austen, writing North- anger Abbey in 1798 when Rumford was at the height of his renown, should have made his practical improvement a means of satirizing her visionary heroine. 1 The Girlhood oj Maria Josepha Holroyd, p. 390. The letter was written from Sheffield Place, Sussex, June 10, 1796. The English edition of Count Rumford's Essays was published in that year, and in 1798 he presented before the Royal Society his notable "Enquiry Concerning the Source of Heat which
is Excited by Friction. "
