Ever wonder why batteries are marked with a “+” and a “-”? There isn’t really anything exactly “positive” or “negative” about electricity; it’s just a convention to describe the directionality of electric charge. When early researchers noticed the directionality, about three centuries ago, they had to call it something, and it was John Bevis, who was born November 10, 1695 in England, who first used the terms positive and negative.
He was working with “Leyden jars” at the time — a Leyden jar is a device for storing an electrical charge. Nowadays we call that sort of thing a capacitor, but at first they were called “jars” mostly because they really were made out of glass jars. Leyden jars are still around, but as far as I know they’re only used for teaching purposes. Or you can make one yourself; you’ll need…a jar. And some other stuff.
But back to Bevis. He was a bit of a Renaissance man, even though he lived long after the actual Renaissance. That is, he was an electrical researcher, but also a doctor, possibly the world’s first seismologist, a biochemist long before anybody thought of that term, and an astronomer. He’s best known, in fact, for his astronomy; he’s the discoverer of the Crab Nebula.
He was also dedicated to recording data, which he did in all of his pursuits. He published an extensive survey of the 1755 earthquake in Lisbon. He proposed that all the astronomers in England (and, presumably, elsewhere) collaborate on a “star atlas,” the Unanographia Britannica. He did it using a system we would call “kickstarter” — he published a newspaper ad requesting backers, and promising that anybody who contributed would get a copy of the atlas. The project had a good start, but unfortunately was never published. Long after his death, though, the notes and charts that he compiled were published as the Atlas Celeste.
Bevis was nothing if not dedicated to his scientific pursuits, and it cost him. He died in 1771 after falling off his own telescope.
