Torrs
The torr is named after Evangelista Torricelli, an Italian physicist who invented the barometer. One torr is the pressure of a 1 millimeter column of mercury at 0 degrees Celsius.
Inches of Mercury
Inches of Mercury (inHg) are used to measure pressure in the imperial system. Traditionally this unit is used in the United States for barometric pressure in weather reports. It is the pressure from a column of mercury exactly one inch high at standard gravity.