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![Figure 38 ship4495.jpg Figure 38](/sites/default/files/styles/max_1300x1300/https/s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_ship4495.jpg?itok=CbYF5x62)
Description
Figure 38. Hygrometer register, built to record variations in relative humidity. The hygrometer is built on principles discovered by Horace Benedict Saussure in 1783 and uses the changes in length of human hair and animal hair with humidity to derive relative humidity. The exact age of this recording instrument isunknown. (Image credit: Oceanographic Museum of Monaco | Y. Berard)