Manometer
an instrument for measuring the elastic force of gases or steam. It consists of a graduated tube in which a body of confined air is compressed by the gas or steam under experimental test, a body of mercury intervening between the air in the tube and the gas or steam whose elastic force is to be ascertained. The tube containing the confined air, of a certain volume at a given temperature, is maintained at the said temperature by a bath, and is tested for the graduation of the tube by means MANOR of a column of mercury. It is then ready for the connection by a tube with the reservoir or boiler which contains the gas or steam whose elastic force is to be ascertained. A steam gauge. Called also a manoscope.