Richard Freres type meteorograph (portable weatherstation) by Richard Frères, Paris, France, 1886-1903

In order to discover the behaviour of the atmosphere at height, scientists developed lightweight equipment which they attached to kites or balloons. Richard Freres was one of the top three makers of the period. This example measured humidity with a hair hygrometer, temperature using a bimetallic strip and pressure using an aneroid capsule.