Coiled Tension

In 1849, an American mechanic named Walter Hunt found himself owing a fifteen-dollar debt to a friend. To pay it off, he took an eight-inch piece of brass wire, coiled it at the center to create a spring, and fashioned a clasp at one end. In exactly three hours, Hunt had invented the modern safety pin-a mechanical masterpiece of tension and simplicity. Desperate for quick cash, Hunt immediately ...