Paper, 'An account of an experiment of the different densities of the air, from the greatest natural heat, to the greatest natural cold in this climate' by Francis Hauksbee Hauksbee writes: 'I took a glass tube about 2 feet in length, and near two tenths diameter; which at about 6 inches from one end, i bent in form of a syphon, as represented by the figure [no figure included with manuscript]: at whole end, which was farthest distant from the angle, I cemented on a brass screw with small perforation in it; by which means, when I put a little quicksilver into the shorter leg, I could by declining the tube, or longest leg, bring it to rest any where; as suppose at A A.' Subject: Physics Read to the Royal Society on 21 June 1704 Published in Philosophical Transactions as 'An account of an experiment touching the different densities of the air, from the greatest natural heat, to the greatest natural cold in this climate' [1704]