Webster
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Webster’s Revised Unabridged Dictionary · 1913

Barometer

Ba·rom′e·ter (bȧ·rŏm′ē·tẽr), n. [Gr. βαρος weight + -meter: cf. F. baromètre.] An instrument for determining the weight or pressure of the atmosphere, and hence for judging of the probable changes of weather, or for ascertaining the height of any ascent.

☞ The barometer was invented by Torricelli at Florence about 1643. It is made in its simplest form by filling a graduated glass tube about 34 inches long with mercury and inverting it in a cup containing mercury. The column of mercury in the tube descends until balanced by the weight of the atmosphere, and its rise or fall under varying conditions is a measure of the change in the atmospheric pressure. At the sea level its ordinary height is about 30 inches (760 millimeters). See Sympiesometer. Nichol.

Aneroid barometer. See Aneroid barometer, under Aneroid. — Marine barometer, a barometer with tube contracted at bottom to prevent rapid oscillations of the mercury, and suspended in gimbals from an arm or support on shipboard. — Mountain barometer, a portable mercurial barometer with tripod support, and long scale, for measuring heights. — Siphon barometer, a barometer having a tube bent like a hook with the longer leg closed at the top. The height of the mercury in the longer leg shows the pressure of the atmosphere. — Wheel barometer, a barometer with recurved tube, and a float, from which a cord passes over a pulley and moves an index.

Webster’s Revised Unabridged Dictionary, Noah Porter, editor (Springfield, Mass.: G. & C. Merriam, 1913). Public domain. Text as transcribed by MICRA, Inc., from Project Gutenberg. Changed for Deep Dive Bible: Greek, which our source spelled in Latin letters, set in Greek letters; entries of one spelling merged into one article; Greek words our source left out (shown as “?”), read from the 1898 printing, from the same plates (the Library of Congress’s copy), where the place could be found with certainty. Of the others, 1,362 (a word or a single letter each) were inferred by AI from the context by the dictionary’s own rules and are marked with a wavy underline (tap or point at one to see the note); the rest, which could not be inferred with confidence, are left as “?”.