FEATURE ARTICLE
Revolutionary Minds
Thomas Jefferson and James Madison participated in a small "revolution" against British weather-monitoring practices
Susan Solomon, John S. Daniel, Daniel L. Druckenbrod
Agreement with the Current Record
The averages of Madison's measurements at Montpelier and Jefferson's at Monticello for each available month of the year (outdoor only) are compared to modern data in Figure 8. The graph shows excellent agreement of the historical and modern data to within a few degrees, attesting to the general quality of the work done by the various Madison family observers as well as by Jefferson, including their own calibration corrections using boiling water.
An independent check on the accuracy of the historic data is provided by comparison of the temperatures on days with snowfall to modern measurements at sites nearby. Snow falls on days typically characterized by specific types of meteorological conditions, and the corresponding characteristic temperatures at the two modern Virginia stations that are closest to the Madison and Jefferson plantations match the historical data well as shown in Figure 8, strongly supporting the accuracy of both instruments. Similar comparisons were used by Gordon Manley in establishing the long-term averages of Central England historical records of temperature.
Is Virginia warmer today than it was a few hundred years ago? Climate studies suggest that human activities have caused a globally averaged warming of the order of 1.5 degrees Fahrenheit due mainly to emissions of greenhouse gases, mostly in the 20th century. Determination of such changes requires a very high level of both precision and accuracy, and care must be exercised in interpreting local data, which can be influenced by such factors as land use and nearby aerosol pollution. A great deal of further analysis beyond the scope of the present work would be needed to determine whether the Jefferson or Madison observations may be of scientific value in the context of the modern challenge of global warming, but it is interesting that the Madison record (which is far more complete than that of Jefferson) is not inconsistent with cooler conditions in the late 18th century, particularly in summer.
Jefferson continued to deal not only with political exchanges with France but also with scholarly ones. In 1805 he wrote to the Comte de Volney, who had written a book about America, including its climate. Volney's work was decidedly less negative than that of his countryman Buffon, and Jefferson wrote: "I have read it, and with great satisfaction." Jefferson also commented on the differences in extreme temperatures between Europe and the United States, noting the importance of adaptation in determining the responses to extremes:
In no case, perhaps, does habit attach our choice or judgment more than in climate.… The changes between heat and cold in America, are greater and more frequent, and the extremes comprehend a greater scale on the thermometer in America than in Europe. Habit, however, prevents these from affecting us more than the smaller changes of Europe affect the European. (TJ to Volney, Feb. 8, 1805)
Both Madison and Jefferson have left confused legacies that have confounded attempts at simple descriptions. Both decried slavery in some of their writings, yet both owned slaves throughout their lives and declined to free them at their deaths. Both embraced ideals that today would be viewed as a mixture of liberal and conservative. Understanding their 18th century characters on a human level will likely continue to challenge people of the 21st century and beyond. But the stark numbers of their meteorological records add a different and objective dimension to their remarkable legacies—and open a window into their revolutionary minds.
Bibliography
- Bedini, S. A. 2002. Jefferson and Science. Monticello Monograph Series.
- Buffon, Comte de (also Leclerc, Georges-Louis). 1764. Histoire Naturelle xviii. 122, ed Paris, 1764.
- Camuffo, D. 2002. Calibration and instrumental errors in early measurements of air temperature. Climatic Change 53:297-329.
- Camuffo, D. 2002. History of the long series of daily air temperature in Padova (1725-1998). Climatic Change 53:7-75.
- Cavendish, H., W. Heberden, A. Aubert, J. A. DeLuc, N. Maskelyne, S. Horsley and J. Planta. 1777. The report of the Committee of the Royal Society to consider of the best method of adjusting the fixed points of thermometers; and the precautions necessary to be used in making experiments with these instruments. Philosophical Transactions 67:816-857.
- Druckenbrod, D., M. E. Mann, D. W. Stahle, M. K. Cleveland, M. D. Therrell and H. H. Shugart. 2003. Late 18th century precipitation reconstructions from James Madison's Montpelier Plantation Bulletin of the American Journal of the Meteorological Society. January 57-71, DOI 10.1175/BAMS-84-1-57.
- Fleming, J. R. 1990. Meteorology in America 1800-1870. Baltimore: Johns Hopkins University Press.
- Jefferson, T. 1784. Notes on the State of Virginia; Written in the Year 1781, Somewhat Corrected and Enlarged in the Winter of 1782, for the Use of the Foreigner of Distinction, in Answer to Certain Queries Proposed by Him. Paris: Privately published.
- Jefferson, T. 1997. Jefferson's Memorandum Books: Accounts, with Legal Records and Miscellany, 1767-1826, ed. J. A. Bear, Jr., and L. C. Stanton. Princeton, N.J.: Princeton University Press.
- Jefferson, T. 1997. The Papers of Thomas Jefferson, ed. Julian Boyd, et al. Retirement series, ed. J. Looney. Princeton, N.J: Princeton University Press.
- Jurin, J. A. 1723. Invitatio ad observations meteorologicas communi consilio instituendas. Philosophical Transactions (32)422-427.
- Madison, J. Jr. 1975. The Papers of James Madison, ed. R. Rutland, W. Rachal, et al. Chicago: University of Chicago Press.
- Manley, G. 1952. Thomas Barker's meteorological journals, 1748-1763 and 1777-1789. Quarterly Journal of the Royal Meteorological Society 78:255-259.
- McLaughlin, J. 1990. Jefferson and Monticello: The Biography of a Builder. New York: Henry Holt and Co.
- Middleton, W. E. K. 1966. A History of the Thermometer and Its Use in Meteorology (esp. Chapter X: Exposure of Thermometers), Baltimore, M.D.: The Johns Hopkins Press.
- Smith, J. M. 1995. The Republic of Letters: The Correspondence Between Thomas Jefferson and James Madison 1776-1826, 3 Vols. New York: W. W. Norton and Company.
- Williams, C. N., Jr., M. J. Menne, R. S. Vose and D. R. Easterling. 2005. United States Historical Climatology Network Monthly Temperature and Precipitation Data. ORNL/CDIAC-118, NDP-019. Oak Ridge, Tenn.: U.S. Department of Energy. http://cdiac.ornl.gov/epubs/ndp/ushcn/usa_monthly.html
- Williams, C. N., R. S. Vose, D. R. Easterling and M. J. Menne. 2006. United States Historical Climatology Network Daily Temperature, Precipitation, and Snow Data.ORNL/CDIAC-118, NDP-070. Oak Ridge, Tenn.: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory.
» Post Comment