SIMS requires a high vacuum with pressures below 10 Pa (roughly 10 mbar or torr). Molecular distillation is vacuum distillation below the pressure of 0.01 torr. Molecular distillation is vacuum distillation below the pressure of 0.01 torr (1.3 Pa). Ordinary plasma etching operates between 0.1 and 5 Torr. One millimetre of mercury is approximately equal to one torr. A torr was originally defined as 1 mmHg. The torr, a unit of pressure used in vacuum measurements, is named after him. It works with a very good quality vacuum (about 10 Pa, or 10 Torr). This metal-to-metal seal can maintain pressures down to 100 pPa (~10 Torr). The torr was then redefined as of one atmosphere. Old English "torr" is from Latin "turris" via Old French "tor". He knew of a Leicester music hall comedian and proprietor named Sam Torr. Merrick wrote to Torr, who came and visited him at the workhouse. The games follow twins named Tarra and Torr. The Rev. Douglas Torr also came out to his congregation in Johannesburg.