Rain-gauge

(-gāj,) or Pluviometer. (Meteor.) An instrument for measuring the fall of rain. The simplest form is a metallic cylinder, with a gla tube (divided into inches and parts) rising from the bottom. Afloat, with an attached scale rising above the level of the rain-gauge, is sometimes used, as the gla tube is apt to break during frosty weather. A rain-gauge must be placed close to the ground, as elevation causes marked diminution in the amount of fall. The cause of this peculiarity has not yet been satisfactorily explained. [s. 752]