< 1 of 1 > Back

made in England

Postcard of Hygrometer.
© National Museums Scotland


A hygrometer is a device for measuring atmospheric humidity. This example was made in England around 1830, to a design by John Frederic Daniell (1790-1845), professor of chemistry at King's College in London from 1831 to 1845. It is unsigned.

The instrument consists of a glass tube containing ether, bent twice at right angles, terminating at each end in a glass bulb, one made of black glass, the other transparent but covered with a piece of muslin. It also contains two thermometers, one on the stem of the brass support, the other inside the tube.

Daniell first published a description of his new dew-point hydrometer in 1820. Its operation depended on the rapid indirect cooling and slow reheating of a black glass bulb. The mean between the temperatures at which moisture first appeared and last disappeared from the surface of the bulb was taken as the dew point. The device proved very popular.

Record details

To search on related items, click any linked text below.

Online ID: 000-100-104-224-C
Image Rights Holder: National Museums Scotland
Project: 0098: National Museums Scotland
Project description | View all records in project
Ref: National Museums Scotland  T.1957.34
Date: Around 1830
c. 1830
Material: Brass pillar and base, glass bottle / mahogany case
Dimensions: 7.00" x 5.50" x 1.75" case
What: Hygrometer, Daniell's / case
Who: Daniell (Eponym)
Where: England
Description: Daniell's hygrometer, with a brass pillar and base, and a glass ether bottle, and all in a fitted mahogany case
  • Daniell, John Frederic. Meteorological Essays and Observations. London, 1823, pp 186-201 
  • Middleton, W. E. Knowles. Invention of the Meteorological Instruments. Baltimore, 1969 p 114-7 
Related Records:
< 1 of 1 > Back
Powered by Scran