1765.
Watt improved the steam engine in 1765. James Watt, a British instrument repairman, repaired the Newcomen steam engine model for the University of Glasgow. In 1765, he invented a steam engine with a condenser separated from the cylinder wall, and obtained a British patent in 1769. The early Watt steam engine still used a balance lever and a tie rod mechanism to drive the water pump. In order to remove the condensed water and air from the condenser, Watt installed an air extraction pump. An interlayer is also installed on the outer wall of the cylinder, and steam is used to heat the cylinder wall to reduce condensation loss.