hypsometer
(hɪpˈsɒmɪtə(r))
[f. Gr. ὕψος height (see hypso-) + -meter. Cf. F. hypsomètre.]
An instrument for measuring altitudes, consisting essentially of a delicate thermometer, by which the boiling point of water is observed at particular elevations.
| 1864 in Webster. 1879 Daily News 23 Aug. 6/4 Major Pinto recommended the hypsometer and aneroids for altitudes. 1884 Brit. Almanac Companion 17 An instrument called the Hypsometer, whose business it is to determine the heights of mountains by means of the boiling-point of water. |