• Webster's Revised Unabridged Dictionary
    • n Barothermograph An instrument for recording both pressure and temperature, as of the atmosphere.
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Century Dictionary and Cyclopedia
    • n barothermograph An apparatus for recording simultaneously the atmospheric pressure and temperature; a combination of barograph and thermograph, especially such as are made portable and very light to be sent up with kites and sounding-balloons. Assmann's barothermograph, used with sounding-balloons, records a pressure - [temperature curve without any time coördinate and by means of one pen only.] The cylinder or sheet of paper is pushed in one direction by the action of the barometer while the pen is pushed in the perpendicular direction by the action of the thermometer. In all other forms of apparatus each instrument makes its own record by its own pen and has its own independent time-scale. Sometimes called meteorograph. Monthly Weather Rev., Sept., 1896, p. 323.
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Webster's Revised Unabridged Dictionary
Gr. weight + thermograph,