Credit: J. Stoughton/NIST Grave, ahoy!

To save his own life, Joseph Dombey had an idea. As two pirate ships surrounded the ship he was on in the Caribbean Sea in 1794, Dombey scrambled below deck, disrobing as he went. He appropriated the outfit of one of the ship’s many Spanish sailors and prayed that he had picked up enough of their language during his trips to South America to blend in. Dombey shouldn’t have been in this position. In fact, he shouldn’t have been in the Caribbean at all. None other than Thomas Jefferson himself was expecting to meet with Dombey in Philadelphia at that very moment.

Left: a bust of Joseph Dombey; Right: Thomas Jefferson, patiently waiting ... Dombey’s fate that day arguably delayed the adoption of the metric system in the United States by almost a century and left us as one of the few countries in the world still using non-metric units for our everyday measurements.

A doomed voyage

The marauders now swarming Dombey’s ship were a particular breed of pirate: British privateers—the state-sponsored terrorists of the 18th century. These waterborne gangs had the tacit approval of the government in London to harass and plunder other countries’ maritime commerce and keep part of the spoils as their profit.

After seizing control of the ship, the pirates came across a sailor speaking Spanish with a curiously French accent—Joseph Dombey. A French physician and botanist acting under orders from the French government, Dombey had left the port city of Le Havre, France, weeks earlier for Philadelphia and the meeting with Jefferson, the United States’ first secretary of state and future president. But storms had pushed Dombey’s ship off course and deep into pirate territory.

France had supported the United States against the British in the War of Independence, and now they intended to build closer economic ties with the new American nation. Dombey was to negotiate with Jefferson for grain exports to France and to deliver two new French measurement standards: a standard of length (the meter) and a standard of mass called, rather ominously, a grave, to be considered by the U.S. for adoption. (The grave would be renamed the kilogram a year later in 1795.)

In many ways, Dombey was an excellent choice for this mission. Having already been on several trips to South America to collect botanical specimens, he was an experienced trans-Atlantic traveler. His knowledge of plants would also be of help in his agricultural trade negotiations with Jefferson. And Dombey’s scientific training as a physician and botanist gave him an understanding of the importance of accurate weights and measures, so it was highly likely that he would be able to convince Congress to adopt the new French standards, which would later come to be known as the metric system.

Despite his qualifications, Dombey lacked one important attribute: luck. His previous trips had all ended in failure. He had spent two years in Peru collecting plants that could be usefully cultivated in France, only to have the shipment captured by the British. A second collecting trip, this time in Chile and in collaboration with Spain, fell apart over a business dispute, with Spain keeping all the valuable specimens. But Dombey’s voyage to Philadelphia would turn out to be his most disastrous.

Credit: David Stanley/CC BY 2.0 Montserrat is a lot nicer when you're not being held for ransom by pirates. Upon learning his true identity, the pirates imprisoned Dombey on the Caribbean island of Montserrat. Unfortunately, Dombey died before they were able to ransom him to the French, and the units of measure in his charge never made it into Jefferson’s hands.

A missed opportunity

Some historians view this event as a tragic missed opportunity whose consequences we are still living with today. When the U.S. became an independent nation, it inherited an inconsistent collection of traditional British weights and measures. Congress was aware of the flaws with its British measures, and a congressional committee was formed to recommend solutions. Thomas Jefferson, an admirer of French scientific ideas, lobbied for a measurement system similar to that of France. But Congress didn’t adopt it, and the British-influenced system took hold in the U.S. instead. However, If pirates hadn’t intercepted Dombey on his way to Philadelphia, the situation might be very different today. As historian Andro Linklater writes in his book Measuring America,

“The sight [in Congress] of those two copper objects [Dombey’s meter and grave], so easily copied and sent out to every state in the Union, together with the weighty scientific arguments supporting them, might well have clarified the minds of senators and representatives alike. And today the U.S. might not be the last country in the world to resist the metric system.”

It would take almost 100 years after Dombey’s failed mission before the United States, with the Mendenhall Order of 1893, officially adopted metric standards as our fundamental standards for weights and measures. While many U.S. industries have since converted to metric, the nation's long history with British-influenced standards has slowed the widespread adoption of metric units in common practice.

The well-traveled grave

Secretary of State Edmund Randolph (1794-1795). Thanks a lot, Edmund. Whatever became of the meter and grave Dombey had with him in 1794? Only six sets of these standards were made. And only Dombey’s set is known to have traveled to the Americas. The cargo on Dombey’s ship was eventually auctioned off. The meter and grave were purchased, and through a series of French intermediaries, the standards were turned over to the next U.S. secretary of state, Edmund Randolph. Randolph failed to understand the significance of the standards and took no action regarding them.

Somehow a grave ended up in the possession of Andrew Ellicott, a contemporary of Dombey and a well-regarded land surveyor. Ellicott surveyed the boundaries for what became Washington, D.C., and completed the street plan for D.C. that had originally been envisioned by Pierre L'Enfant. The grave remained in the Ellicott family until 1952 when his descendant Andrew Ellicott Douglass donated it to the NIST museum.

Is the grave now on display in the museum the same one captured by pirates in 1794? That remains a mystery.