Academic journal article The Science Teacher

Right to the Source

Academic journal article The Science Teacher

Right to the Source

Article excerpt

Thomas Jefferson, Data Collector

In May 1776, Thomas Jefferson arrived in Philadelphia. Soon the young delegate to the Continental Congress was drafting the Declaration of Independence. Somehow he also found time to buy a thermometer and, on July 1, to start collecting weather data. Today, a notebook of Jefferson's weather records is in his papers at the Library of Congress.

In a 1790 letter to his son-in-law, Thomas Mann Randolph, Jefferson explained that column one in his weather record (shown at right) was for the date; columns two and four, morning and afternoon temperature readings; and columns three and five, weather observations in shorthand: a = after, c = cloudy, f = fair, h = hail, r = rain, s = snow. "Thus c a r h s means, cloudy after rain, hail, and snow," Jefferson wrote. Column six was for "miscellanies, such as the appearance of birds, leafing and flowering of trees, frosts remarkeably late or early, Aurora borealis, &c."

Later, Jefferson acquired a barometer and hygrometer so he could record atmospheric pressure and humidity, respectively. In June 1778, he expanded his record to 11 columns, adding wind force and direction, and the first and last seasonal appearances of "leaves, flowers, wild fruit," birds, and insects. In 1799, he noticed that two thermometers on the northeast portico of Monticello had been "artificially heated," he believed, by a "mound of earth." In the notebook he drew lines through months of incorrect temperature readings.

The notebook contains not only weather data but also notes, lists, and calculations stretching to 1818. Jefferson included weather data provided by others, a clue to his broader scientific goal of comparing data from different places. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.