ATMOM′ETER

Syn. Atmidom′eter ; Atmom′etrum , ., L.; Atmomètre , ., Fr. In chemistry and meteorology , an instrument for measuring the rate of evaporation from a humid surface. It is of very simple construction, and po e es some practical value. It consists of a long gla graduated tube divided into inches, having attached to the bottom a hollow ball made of porous earthenware, similar to that used in water bottles. When used, water is poured in at the top until it rises to the zero point of the scale. The outside of the porous ball being always covered with dew, the more rapidly the evaporation takes place, the more quickly will the water fall in the tube.