Heron of Alexandria (circa 10CE to 70CE)
You are at a train station. You feel peckish but to your consternation the queue at the kiosk is too long. You spot a vending machine. You fumble in your pocket, extract a coin and put it into the slot. If you are lucky your coin is accepted, you make your selection and, hey presto, your snack pops out of a dispenser, leaving you just enough time to catch your train.
The first modern coin-operated vending machine was invented by Percival Everitt in 1883 and soon appeared on railway stations dispensing envelopes, postcards and notepaper. The first American version was built by the Thomas Adams Gum Company in 1888 and was used to dispense gum on New York railway platforms. Brass portable coin-operated machines were to be found as early as 1615 in English taverns, from which you could get your tobacco and Simeon Denham secured a patent in 1867 for his stamp machine, the first fully automatic vending machine.
But the idea of having a machine that was coin-operated goes back to the first century of the Christian Era and was the brain child of inventor and mathematician, Heron, who lived in one of the intellectual powerhouses of the Roman Empire, Alexandria. In his book Mechanics and Optics he described a coin-operated machine which dispensed a quantity of holy water. When the coin was deposited into the top of the machine, it fell on to a pan attached to a lever. The lever opened up a valve allowing the water to flow out. The pan continued to tilt until the coin fell off causing a counter-weight to snap the lever back up and turn off the valve.
The harnessing of steam power, thanks to the likes of James Watt, was a key factor that led to what we call the Industrial Revolution in Britain. But Heron had got there first too, with his aeolipile. This consisted of a sphere which either contained water that was boiled or had pipes attached to a tank underneath in which the water was boiled. Two nozzles opposite each other in the sphere would expel steam and after a while sufficient force would be generated to spin the it around its axis. A replica of his specification has been built and rotated at 1,500 rounds per minute with a very low pressure of 1.8 pounds per square inch. It was not until 1577 that Taqu al-Din picked up Heron’s mantle and developed a mechanism for rotating a spit using steam.
If you think that was enough, Heron wasn’t finished, not by a long chalk. He described a syringe-like device which could be used for the dispensing of air or liquids. He came up with possibly the first wind-operated machine, one that harnessed the wind to power an organ. And we shouldn’t forget his stand-alone fountain which used its own hydrostatic energy.
In the field of mathematics he described a method for iteratively calculating the square root of a number and developed a formula for finding the area of a triangle from the length of its sides. And in optics he formulated the principle of the shortest path of light, and idea that was not picked up and developed to include reflection and refraction for nigh on a thousand years, by Alhacan.
You cannot help wonder what the world would have been like today, had Heron’s ideas not lain on the dusty shelves of the library at Alexandria for centuries.