Found on The Verge:
The legendary watchmaker's design was centuries ahead of its time.
John Harrison, one of the world's greatest clockmakers, claimed to have designed the perfect pendulum clock in the mid-18th century. Instead of being celebrated, Harrison's plans were chastised and ridiculed by his peers. A clock that was accurate to within a second over a 100-day period was unheard of, and a mechanical clock that precise wouldn't be developed until the 20th century. But after a 100-day trial at the Royal Observatory in Greenwich, Clock B as it's known — which was recently constructed to Harrison's specifications — has vindicated Harrison, set a Guinness World Record, and shocked the horological world, according to The Guardian.