photoheliometer

Noun

Meaning

photoheliometer (plural photoheliometers)

(historical) A double-lens instrument for measuring slight variations of the Sun's diameter by photography, based on the common chord of two overlapping images.

Source: en.wiktionary.org

Close letter words and terms

photoheliograph photoheliographic photoheliography photohemolysis photohemolytic photoheterotroph