Thomas Jefferson Papers

Thomas Jefferson to Nathaniel Chapman, 11 December 1809

To Nathaniel Chapman

Monticello Dec. 11. 09.


Your favor of Nov. 10. did not come to hand till the 29th of that month. the subject you have chosen for the next Anniversary discourse of the Linnean society, is certainly a very interesting, & also a difficult one. the change which has taken place in our climate is one of those facts which all men of years are sensible of, & yet none can prove by regular evidence. they can only appeal to each other’s general observation for the fact. I remember that when I was a small1 boy (say 60. years ago) snows were frequent and deep in every winter; to my knee very often, to my waist sometimes, and that they covered the earth long. and I remember, while yet young, to have heard from very old men that, in their youth, the winters had been still colder, with deeper & longer snows. in the year 1772. (37. years ago) we had a snow 2. feet deep in the Champain parts of this state, & 3. feet in the counties next below the mountains. that year is still marked in conversation by the designation of ‘the year of the deep snow.’ but I know of no regular Diaries of the weather very far back. in latter times they might perhaps be found. while I lived at Washington, I kept a Diary, & by recurring to that I observe that from the winter of 1802.3. to that of 1808.9. inclusive, the average fall of snow of the 7. winters was only 14½ Inches, & that the ground was covered but 16. days in each winter on an average of the whole. the maximum in any one winter during that period was 21.I. fall, & 34. days on the ground; the minimum was 4½ I. fall & 2. days on the ground. the change in our climate is very shortly noticed in the Notes on Virginia, because I had few facts to state, but from my own recollections, then only of 30. or 35. years. since that my whole time has been so compleatly occupied in public vocations, that I have been able to pay little attention to this subject; &, if I have heard any facts respecting it, I made no note of them, & they have escaped my memory. Thus, Sir, with every disposition to furnish you with any informations in my possession, I can only express my regrets at the entire want of them. nor do I know of any source in this state, now existing, from which any thing on the subject can be derived. Williams, in his history of Vermont, has an essay on the change of climate in Europe, Asia, & Africa, & has very ingeniously laid history under contribution for materials. Doctr Williamson has written on the change of our own climate, in one of the early volumes of our Philosophical transactions. both of these are doubtless known to you.

Wishing it had been in my power to have been more useful to you, I pray you to accept the assurance of my esteem & respect.

Th: Jefferson

PoC (DLC); at foot of first page: “Dr Chapman.”

TJ’s weather diary (MHi) includes a “Recapitulation of the depth of the snows which fell & of their continuance on the ground” in the nation’s capital. In his notes on virginia, TJ asserted that snows had become “less frequent and less deep” and that rivers seldom froze in the winter or overflowed their banks in the spring due to melting snow (Notes, ed. Peden description begins Thomas Jefferson, Notes on the State of Virginia, ed. William Peden, 1955 description ends , 80). Samuel williams discussed the change of climate in The Natural and Civil History of Vermont (Walpole, N.H., 1794; Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952–59, 5 vols. description ends no. 457), 57–65. Hugh williamson published his August 1770 essay, “An Attempt to account for the Change of Climate, which has been observed in the Middle Colonies in North-America,” in APS description begins American Philosophical Society description ends , Transactions 1 (1771): 272–80. With only modest revisions it was reprinted in 1772, 1789, and, as Observations on the Climate in Different Parts of America, compared with the Climate in Corresponding Parts of the Other Continent, in New York in 1811 (Ralph H. Brown, “The Seaboard Climate in the View of 1800,” Annals of the Association of American Geographers 41 [1951]: 228).

1Word interlined.

Index Entries

  • American Philosophical Society; Transactions search
  • Chapman, Nathaniel; and meteorology search
  • Chapman, Nathaniel; letters to search
  • Jefferson, Thomas; Opinions on; climate change search
  • Jefferson, Thomas; Writings; Notes on the State of Virginia search
  • Jefferson, Thomas; Writings; Weather Memorandum Book search
  • Linnean Society of Philadelphia search
  • meteorological observations; by H. Williamson search
  • meteorological observations; by S. Williams search
  • meteorological observations; by TJ search
  • meteorological observations; N. Chapman seeks search
  • Notes on the State of Virginia (Thomas Jefferson); and climate change search
  • Observations on the Climate in Different Parts of America (Williamson) search
  • Philadelphia; Linnean Society of search
  • The Natural and Civil History of Vermont (S. Williams) search
  • Virginia; snowfall in search
  • Washington (D.C.); snowfall in search
  • weather; and climate change search
  • weather; snow search
  • Williams, Samuel (1743–1817); The Natural and Civil History of Vermont search
  • Williamson, Hugh; Observations on the Climate in Different Parts of America search