Who invented the hygrometer?
Horace Bndict de Saussure, a Swiss physicist and geologist, invented the first hygrometer to measure humidity in 1783. He used human hair as a critical part of his hygrometer after noticing that it becomes longer in air with high humidity and shorter with low humidity. Horse hairs, metallic and infrared sensors can substitute for human hairs. Hygrometers and other weather instruments are explained on the Measuring weather page.
