inch of mercury

noun

1. a unit of atmospheric pressure, being the pressure equal to that exerted by a column of mercury one inch high under standard conditions of temperature and gravity: 33.864 millibars. : in. Hg

Word History and Origins

Origin of inch of mercury¹

First recorded in 1825–35

Example Sentences

He could reduce the pressure in the large receiver to somewhat less than that corresponding to an inch of mercury, or about a foot of water.

From Project Gutenberg

A cubic inch of mercury at this temperature has been ascertained to weigh 0·48967 lbs. avoirdupois.

From Project Gutenberg

Now, when the barometer falls from 30 to 29 inches, an inch of mercury must flow out of the tube and pass into the cistern, thus raising the cistern level; and, on the other hand, when the barometer rises, mercury must flow out of the cistern into the tube, thus lowering the level of the mercury in the cistern.

From Project Gutenberg

Bartrum it is claimed that readings to .001 of an inch of mercury can be taken without the use of a vernier.

From Project Gutenberg

About thirteen minutes after the great outburst, this gauge showed a barometric disturbance equal to about four-tenths of an inch of mercury, that is, an extra air pressure of about a fifth of a pound on every square inch.

From Project Gutenberg