Thomas Jefferson - The Amateur Astronomer

Jack Kramer

Earlier this year while on vacation in Virginia, my wife and I visited Monticello, the home of Thomas Jefferson. Besides being a statesman and third president of the United States, he was a gentleman farmer, lawyer, writer, philosopher, scientist, inventor and architect. I knew he was also an amateur astronomer, but seeing his telescope was a nice surprise, since many of his possessions had been sold off after his death to pay the family's debts. The telescope, shown here, appears to have an objective lens of about 2-inches in diameter and the telescope tube and mount is made mainly of brass. Perhaps not surprisingly, he actually designed the telescope, which is achromatic. He also designed and invented clocks, a dumbwaiter, a polygraph machine, Venetian blinds, and the moldboard for a plow. He built his own astronomical clock because his old less-accurate clocks caused him to miss the eclipse of 1811.

Jefferson had another telescope, referred-to as a "micrometer", which is also on display at Monticello. This one was given to Benjamin Franklin by the French astronomer Alexis Rochon; it was inherited by Francis Hopkinson, and then given to Jefferson. It has a 2-1/6-inch objective lens of Icelandic crystal. The telescope tube is composed of brass, leather, pressed board, paper, and textile; it folds from an open length of 19-inches down to 14-inches.

It's nice to know we can number Thomas Jefferson among our fellow hobbyists!

Published in the November 2006 issue of the NightTimes