July 17, 2011

Banned: The Mercury Thermometer



Oct. 7, 1791: We lifted anchor at 6 am and had a contrary wind…At noon the thermometer marked 55 degrees…Oct. 8: We lifted anchor at 6 am with a wind not quite as bad as evening before…at 11:30 and the thermometer is 59 degrees. Stormy weather and wind from the south west…Oct. 9: They lifted anchor at 8 a. m. with the high tide…at 11:30… The thermometer marks 50 degrees; rain wind from the southwest.

Oct 16: The thermometer marks 39 degrees…At 8:00 p. m. returned and went to bed. Good weather the whole day but cold. An hour after a clumsy person touched the thermometer and we all saw it fall and break.

Oct  17: At 3 a.m…We’ve been deprived of the thermometer so we can no longer give you the certain results of the temperature but we continue to make our observations in comparison from the days past. Winds from the NW this morning and the cold ice (a line and a half of ice).  At noon a bad wind, hail and snow. It just passed through. The same temperature about for the rest of the day.

     Madame Rosalie de Leval was a refugee of the French Revolution who had a tentative contract with land speculators Gen. Henry Knox and Col. William Duer to purchase a large tract of land in Downeast Maine—current day Hancock and Washington counties. It was 1791.

     The contract was tentative because Madame wanted to examine the land before she finalized the purchase. The excerpt above is from the journal she kept of her visit to Downeast Maine for this purpose.

     As can be seen, she was meticulous about recording the temperatures during her travels. However, oops, an oaf dropped the thermometer, and she could only estimate the temperature after that incident.

     What happened to the thermometer? Did Madame, the oaf, or someone else pick up the mercury with their bare hands? Was the thermometer and its contents disposed of by being tossed into the water of the Narrows or Frenchman Bay? Was she, or anyone else, aware that to do so was to pollute the waters with mercury?


     Daniel Gabriel Fahrenheit invented the mercury thermometer in 1714. French emigrants who purchased the invalid Ohio deeds included craftsmen in thermometer making. In 1792 a visitor to Gallipolis wrote We rode to the French settlement of Gallipolis, situated on the north bank of the Ohio, between three and four miles from the Kanawha… The worker in glass seemed to be a born artist. He made us a thermometer, a barometer…


     Perhaps you have a mercury thermometer in your medicine cabinet. I know I still do. But by the time Fahrenheit’s thermometer reaches three hundred years of age, it will be extinct. As of  March 1, 2011, retail sales of these thermometers in a wide variety of industries (as well as many other measuring devices, thermostats and switches, using mercury) have been banned or restricted in at least (more…)

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