Hello and welcome to a history of the United States. Episode 191. How about this weather?

On the morning of the 4th July, 1776, there was something on the mind of Thomas Jefferson.

He had something he urgently needed, and so he went out to Sparhawks, a nearby stationery store in Philadelphia, to buy himself a new thermometer.

He was then able to note that the ambient temperature was 72.5 degrees Fahrenheit.

Now, I know what you're thinking.

There's something odd about this recollection of the 4th of July, 1776.

Jefferson recognized it too.

The very next day, he went back to Sparhawks to buy a barometer

to improve his records. He couldn't be recording temperature without atmospheric pressure.

You see, Thomas Jefferson was keenly interested in the climate and was concerned about climate

change.

He recorded the temperature twice daily for the next 50 years, so he could monitor the situation

firsthand.

He wasn't alone.

Benjamin Franklin thought that humans were changing the climate in North America. His theory

was that when humans cleared trees, it meant that the sun could heat the ground more quickly,

which would more quickly melt winter snows and lead to generally mild weather.

This was also argued by Samuel Williams of Harvard, but also mocked by Noah Webster,

he of the dictionary.

Webster said, quote, Mr. Jefferson seems to have no authority for his opinions, aside from the observations of elder and middle-aged people.

Webster was quite right in some regard.

Samuel Williams claimed that temperatures had increased by 12 degrees in the past 150 years,

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