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barograph

(Encyclopedia)barograph, instrument used to make a continuous recording of atmospheric pressure. The pressure-sensitive element, a partially evacuated metal cylinder, is linked to a pen arm in such a way that the v...

pitot static system

(Encyclopedia)pitot static system pētōˈ [key], device for measuring the rate at which a fluid flows. Among the principal applications of the device are an airspeed indicator for aircraft and a distance and speed...

STP

(Encyclopedia)STP or standard temperature and pressure, standard conditions for measurement of the properties of matter. The standard temperature is the freezing point of pure water, 0℃ or 273.15K. The standard...

Hewitt, Peter Cooper

(Encyclopedia)Hewitt, Peter Cooper hyo͞oˈĭt [key], 1861–1921, American scientist and inventor, b. New York City; son of Abram S. Hewitt and grandson of Peter Cooper. He invented a mercury-vapor lamp and a merc...

Hofmann, August Wilhelm von

(Encyclopedia)Hofmann, August Wilhelm von ouˈgo͝ost vĭlˈhĕlm fən hôfˈmän [key], 1818–92, German organic chemist. He was professor at the Univ. of Berlin from 1865 and was a founder (1868) of the German C...

lewisite

(Encyclopedia)lewisite lo͞oˈəsītˌ [key], liquid chemical compound used as a poison gas. Like mustard gas and nitrogen mustard, it is a blistering agent; when inhaled, it is a powerful respiratory irritant. The...

Dalton's law

(Encyclopedia)Dalton's law [for John Dalton], physical law that states that the total pressure exerted by a homogeneous mixture of gases is equal to the sum of the partial pressures of the individual gases. The par...

Bourdon gauge

(Encyclopedia)Bourdon gauge: see pressure.

Dumas, Jean Baptiste André

(Encyclopedia)Dumas, Jean Baptiste André dümäˈ [key], 1800–1884, French organic chemist. He was distinguished for his researches on atomic weights, esters, vapor densities, the oxidation products of alcohols...

Irazú

(Encyclopedia)Irazú ēräso͞oˈ [key], active volcano, c.11,260 ft (3,430 m) high, central Costa Rica, E of San José. A massive volcano, Irazú erupted in 1723, destroying Cartago, and since then it has erupted ...