Jefferson's Inventions

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Thomas Jefferson designed and changed many things. But he only thought up three things that could be called inventions. These are the moldboard of least resistance, the cipher wheel, and the spherical sundial.

Moldboard of Least Resistence Plow

Moldboard of Least Resistance Plow

A recreation of a plow using Jefferson's Moldboard of Least Resistance
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Moldboard of Least Resistence

Jefferson was always thinking of ways to improve farming. He invented a new type of moldboard for a plow. A plow is used to dig and turn over the soil for planting. The front of the plow digs up the soil. The moldboard is the curved part that turns the soil. Jefferson said that his moldboard was “so light that two small horses or mules draw it with less labor.” France’s Society of Agriculture awarded him a gold medal for the design.

Recreation of Jefferson's Wheel Cipher

Recreation of Jefferson's Wheel Cipher

A recreation of the Wheel Cipher Jefferson described in an undated manuscript.
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Wheel Cipher

During the American Revolution, soldiers sent messages in code. Codes are used to write secret messages. Jefferson created the wheel cipher. It was one way to write a secret message.

The wheel cipher had 26 wooden disks. The disks were joined by an iron pin. All the letters of the alphabet were imprinted on the edge of each disk in no special order.The letters spun around the iron pin. Words could be scrambled and unscrambled. The person who received a coded message used the cipher wheel to help read the secret message.

 

Recreation of Jefferon's Spherical Sundial and pedestal

Recreation of Jefferson's Spherical Sundial and pedestal

A recreation of Jefferson's Spherical Sundial based on his specifications.
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Spherical Sundial

Jefferson made his sundial from the top part of a column. He placed a globe-shaped ball on top. He marked the North Pole and the South Pole. He marked the equator and the meridian lines. A movable meridian cast a shadow telling the time.

Throughout his life, Thomas Jefferson dreamed, designed, changed and invented. With the help of craftsmen and workers, many of his ideas became real things. Today we can visit Monticello. We can tell time using the Great Clock. We can see many of the gadgets that Jefferson created.