• Webster's Revised Unabridged Dictionary
    • n Brontograph (Meteor) A tracing or chart showing the phenomena attendant on thunderstorms.
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Century Dictionary and Cyclopedia
    • n brontograph Same as brontometer.
    • n brontograph An apparatus devised by Marvin (1899) for recording any wave of sound, as thunder or the discharge of a cannon.
    • n brontograph A map or diagram showing the progress of the front of a thunder-storm by means of isobronts or equivalent lines for successive hours.
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Webster's Revised Unabridged Dictionary
Gr. thunder + -graph,