FRANKLIN, BENJAMIN. 1706-1790.
Autograph Letter Signed ("B. Franklin"), 3 pp recto and verso, folio, London, February 28, 1768, to Lord Kames, discussing "Neighbor Smoke," the problem of smoke from neighboring chimneys being drawn into ones own rooms, with a secretarial letter from Franklin 3½ pp (recto and verso), folio, to Alexander Dick, "Copy Letter from Dr Franklin about his Chimney Machines 21 January 1762," and partial address leaf addressed to Lord Kames, address leaf laid down, letters with edges and folds on second leaves reinforced, not affecting text.
Benjamin Franklin writes to his close friend, Lord Kames, an associate of David Humes and Adam Smiths and a key figure in the Scottish Enlightenment. Kames has recently moved to a new home and Franklin writes in response to his grievance with the phenomenon of "Neighbor Smoke." Franklin provides an explication of the problem and the key to its solution, but not before reflecting on the importance of suchlike small comforts in constituting human happiness: "I have long been of an opinion similar to that you express, and think happiness consists more in small conveniences or pleasures that occur every day, than in great pieces of good fortune that happen but seldom to a man in the Course of his Life. Thus I reckon it among my Felicities that I can set my own Razor and shave myself perfectly well, in which I have a daily Pleasure, and avoid the Uneasiness one is otherwise obligd sometimes to suffer from dull Razors, and the dirty Fingers or bad Breath of a slovenly Barber."
Most of the letter comprises Franklins lengthy scientific explanation. In part: "The Inconvenience you mention of Neighbor Smoke coming down the Vents is not owing to any bad Construction of the Vent down which it comes, and therefore not to be remedied by any Change of Form. It is merely the Effect of a Law of Nature, whereby whenever the outward Air is warmer than the Walls of the Vent, the Air included being by those Walls made colder, and of course denser and heavier, than an equal Column of the outward Air, descends into the Room, and in descending draws other Air into the Vent from above to supply its Place; which being in its Turn cooled and condensed by the cooler Walls of the Vent, descends also, and so a Current downwards is continued during the Continuance of such Difference in Temperament between the outward Air and the Walls of the Vent. When this Difference is destroyd, by the outward air growing cooler and the Walls growing warmer, the Current downward ceases
." Franklin continues by giving his observations as to the time of day and season and locations in the house when and where "Neighbor Smoke" prevails. He concludes by suggesting that the best solution is simply to cover the grate when the vent walls are cold and that: "The Philadelphia Grate which you mention, is a very good Thing, if you could get one that is rightly made and an ingenious workman to fix it properly. Those generally made and used here are much hurt by fancied Improvements in their Construction, and I cannot recommend them. As fuel with you is cheap and plenty, a Saving in that Article is scarce an Object. The Sliding Plates (of which I send a Model to Sir Alexr. Dick) are in my Opinion the most convenient for your purpose, as they keep a Room sufficiently warm, are simple Machines, easily fixd, and their Management easily conceivd and understood by Servants." Franklin encloses a scribal copy of his letter to Sir Alexander Dick detailing his invention of a sliding chimney plate which is also present also in this lot. In addition to his lengthy scientific dsicourse, Franklin alludes twice to disputes between Britain and the American colonies. Published in The Papers of Benjamin Franklin, vol 15, p 60ff. The "Philadelphia Grate" is also discussed in Franklins Experiments and Observations on Electricity. The letter to Dick is published in The Papers of Benjamin Franklin, vol 10, p 13ff.