GAS PRESSURE • E-FREE TRANSLATION.COM • Definition of Gas pressure

... same level in both arms, but when the cock is opened, the gas whose pressure is being measured forces the mercury up the opposite arm. If the pressure of the gas is small, the mercury changes its level but very little. It is clear that the height of a column of mercury is a measure of the gas pressure. Now it is known that one cubic inch of mercury weighs about half a pound. Hence a column of mercury one inch high indicates a pressure of about one half pound to the square inch; a column two inches high indicates a pressure of about one pound to the square ...

— General Science • Bertha M. Clark

... hesitation, though he knew the supreme danger. The letter goes on. "There was a disconnected four-inch pipe, with a pressure of 125 pounds to the inch, in the building, and Constable Moorehead could see one of the bodies moving and he thought there was life." It was probably being moved by the terrific gas pressure. "Moorehead placed his hat over his mouth and went in; on getting near the bodies the jet of gas struck him and blew him to the other side of the building; there he groped for the door, but was too nearly ...

— Policing the Plains - Being the Real-Life Record of the Famous North-West Mounted Police • R.G. MacBeth