Thomas Jefferson’s Life as an Inventor

Thomas Jefferson designed and adapted many things. But only three true inventions — moldboard of least resistance, the cipher wheel, and the spherical sundial — can possibly be credited to him, and only the first of these is certain.


Jefferson was constantly thinking of ways to improve farming. He invented a new type of moldboard for a plow. The moldboard is the curved part that turns over the soil, which the front end of the plow digs up. Jefferson said that his moldboard was “so light that two small horses or mules draw it with less labor than I have even before seen necessary. It does beautiful work and is approved by everyone.” France’s Society of Agriculture awarded him a gold medal for the design.

A recreation of a plow using Jefferson’s ‘Moldboard of Least Resistance’


During the American Revolution, codes were a secure way to send secret messages. While Jefferson was Secretary of State, he wrote instructions for making a cipher wheel, but did not make it known. Jefferson’s wheel cipher was made up of 26 wooden disks 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. Whoever received a coded message also had a cipher wheel to help decode the secret message.

Jefferson’s instructions for making the wheel cipher are the earliest known description of the device. Many historians believe he invented it, but they cannot say so for certain. Similar devices are still in active use and may have been used even before the American Civil War.

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


Jefferson wasn’t the first person to design a spherical sundial. But like most people then, he didn’t know it had already been invented. As far as we know, he thought up the idea on his own. About his sundial he wrote, “my dial captivates every body foreign as well as home-bred, as a handsome object & accurate measurer of time.”

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

Throughout his life, Thomas Jefferson dreamed, designed, drafted, adapted and invented. With the help of free and enslaved craftsmen and workers, many of his ideas became reality. Fortunately, Monticello and all the gadgets within it have been preserved as testimony to his genius.

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

Things Jefferson Might Have Improved Upon

There are a few items Jefferson used and very well may have altered to meet his needs, but there’s no definitive proof that he did so:

  • The swivel chair. We know that Jefferson used a swivel chair, and there’s reason to believe he might have influenced the design for one particular type of revolving armchair. However, contrary to what I’ve read (and, ahem, written), Jefferson did not invent the very first swivel chair.
  • The dumbwaiter. In Jefferson’s day, dumbwaiters were already being used in France and England, but what they normally called a “dumbwaiter” was basically a multi-shelf cart on wheels. Jefferson used those; he also had revolving shelves built into the dining room at Monticello that could be loaded without the guests seeing the slaves who did the actual work. In addition, he had a pulley-driven mini-elevator just for wine bottles that is more like what we would today call a dumbwaiter, but it’s unclear to what extent Jefferson himself was involved in its design.
  • The pedometer. In 1525 by a Frenchman named Jean Fernel invented a device for counting steps, although the original idea for a pedometer can be traced back to none other than Leonardo da Vinci. Jefferson’s involvement was to bring a pedometer, of an entirely different design from what Fernel created, from France to the United States. Jefferson may have improved the design, but we have no definitive evidence that he did. Several other people also claim to have invented the pedometer, and those claims are not exactly untrue, in that there have been numerous unique design approaches to accomplish the same underlying task.

Things I’m Very Sorry to Say Jefferson Just Didn’t Invent

Countless websites (including, ahem, one of mine) have attributed to Thomas Jefferson a few inventions that he simply was not responsible for, namely:

  • A macaroni extruding machine. Oh yes, Jefferson had one, all right, and he was by all accounts quite fond of pasta, but the machine he owned was acquired from an Italian source, shipped to the U.S., and assembled there. It wasn’t Jefferson’s design, although he did indeed make a drawing of such a machine. Although I can’t tell for certain from the drawing, my impression is that this extruder doesn’t make pasta tubes, and certainly not the elbows we most commonly refer to as “macaroni” today.
  • The recipe for macaroni and cheese. I wanted this to be true. I truly did. But there’s just no evidence to support it. Jefferson may well have helped to popularize macaroni (in one form or another), but he was certainly not the first person to combine pasta and melted cheese.
  • The hideaway bed. I have found no evidence that Jefferson even used or owned, let alone invented, any form of hideaway bed. He did, however, have an alcove bed situated between two rooms, and some people apparently believed he had a mechanism to hoist the bed into the ceiling, though none was ever found.