Last night, my coworker Raphael Orlove and I went down to the neighborhood bar for a spot of traditional pub trivia. The kindly quizmaster queried as to who invented the odometer. It doesn’t matter what we responded with, because the “correct” answer—given as Benjamin Franklin—was WRONG. This is a pernicious myth that MUST be corrected. Ben Franklin didn’t invent the odometer at all.
(Now, am I using this large and let’s just say “highly respected” car blog to achieve some modicum of incredibly petty rectitude over a GRIEVOUS bar trivia question? Maybe! But what are blogs for, if not this?)
Benjamin Franklin, American statesman, guy on the money, and general weirdo did use an odometer for measuring the distance between postal routes. But he was hardly the inventor of a device. After all, it’s not like he was the first person throughout the entirety of human history to first go “I would like to know how far I’ve traveled.” Much in the same way that Elon Musk did not invent the subway when he started digging holes in the ground, Franklin did not invent the odometer.
It’s also not a terribly complex concept. If you have an idea of the circumference of a wheel, it’s not too much of a stretch to figure out how many times that wheel must turn before it’s gone a given distance.
The “official” honor for inventor of the odometer is about as definite as anything in the history of technology (not very), but we do know of a number of devices invented thousands of years ago that fit the bill. There was a kind of naval odometer, invented a guy named Vitruvius somewhere between 27 and 23 B.C., which used a system of paddle wheels attached to the sides of a ship. Another early odometer was invented by a guy named Heron (also known as Hero of Alexandria) sometime around the birth of Jesus, according to Cesare Rossi, Flavio Russo, Ferruccio Russo of the University of Naples:
The odometer by Heron is, without any doubt, the predecessor of the modern mechanical mileometer and tripmeter used by modern vehicles tell less than 10 years ago. Although it was designed about 200 [sic, they meant 2000] years ago, it works with the same principles of modern tripmeters.
The device invented by Heron could be attached to a Roman carriage and, using a complex system of gears and pins, could be used to accurately measure distance traveled. Heron went on to invent the steam engine, so you could say the guy had a brain.
But like I said, the question of how far you’ve traveled wasn’t exactly an uncommon one. Zhang Heng, an inventor in China who lived from 78 A.D. to 139 A.D. also invented the odometer, independent of what was going on in Rome at the same time, as Marilyn Shea from the University of Maine – Farmington points out:
In mathematics he estimated the value of π pi as the square root of 10 or 3.1622. He invented a cart to measure lǐ 里, the Chinese mile. (Three Chinese li are roughly equivalent to an English mile.) It was the first odometer.
But not even Vitruvius, Heron, or Zhang may have been the ones to first actually invent the thing. The honor probably goes even further back. But it gets murky.
Even before the time of Ancient Rome, it’s entirely plausible that the Ancient Greeks were using odometers centuries before Vitruvius. The evidence around their use circles around people known as “bematists,” who specialized in measuring distances. The traditional method to figure out how far they went was that the bematists actually counted out their steps. If they knew how big their feet were, and how long their stride was, the general idea was that they could then just count how far they’d gone.
Which all sounds well and fine in an ideal world, where people just sort of walk around on an infinite flat plane and they don’t get tired or whatever. But the world is messy, full of lumps and bumps, ups and downs. Throw in a few hills and ruts, and the whole system could potentially be thrown off. As Christopher Mattew points out in his book An Invincible Beast: Understanding the Hellenistic Pike Phalanx in Action, the bematists were probably doing more than just counting for thousands of miles:
The bematists were specialist surveyors – trained to walk with a regular, measured step so that accurate distances could be recorded. Several such surveyors accompanied Alexander’s expedition into Persia. Many of the measurements recorded by bematists were later recounted in the works of Pliny and Strabo. Engels suggests that the high level of accuracy in the recorded measurements taken by the bematists may be an indication that they used a specific measuring tool to make their calculations – such as the odometer described by Heron of Alexandria.
Mattew goes on to add that the measurements of the bematists fell within a margin of error of only a few percent, over thousands of miles.
Which is pretty much what you’d expect out of an ancient odometer, even though no one mentioned using one. Over the next few thousand years, there were various improvements made by everyone from Blaise Pascal to Thomas Savery.
But did Ben Franklin invent the odometer? No. Definitely did not.
In fact, no one really knows who did.
But that’s where the odometer in your car comes from. And how you know our bar trivia was wrong.