De Sausure hair hygrometer, 1801-1830.

De Sausure hair hygrometer, 1801-1830.
3 2 c m
40cm
actual image size: 32cm x 24cm

Description

In 1783, Horace Benedict de Sausure (1740-1799), a Swis physicist and geologist, made the first hair hygrometer, using a human hair to measure humidity. This type of mechanical hygrometer makes use of the principle that organic substances expand and contract according to changes in relative humidity. The device was calibrated by exposing it to extremes of total saturation and dehydration, thereby establishing the hair's length at 0 and 100 % humidity respectively. Made by Harris. Shown in its case.

Image Details

Image Ref.
 
10316560

© Science Museum / Science & Society Picture Library

buy a print

Select size
 
Select finish
 
How many prints?
 
£20.00
 

buy a framed print

buy a canvas

buy a framed canvas