It was invented by a carpenter in Bury in 1896 called Brian Gamlin. If you go around the dart board adding up the differences between adjacent numbers – 20 and 1 for example – it would come to 198. The highest possible it could come to is 200, but it’s well organised to reduce the chance of a lucky shot.
Discovery of Oxygen. Oxygen was discovered in 1774 by Joseph Priestley in England and two years earlier, but unpublished, by Carl W. Scheele in Sweden. Scheele heated several compounds including potassium nitrate, manganese oxide, and mercury oxide and found they released a gas which enhanced combustion.