Pho`to*he`li*om"e*ter (?), n.
[Photo- + heliometer.] (Astron.) A double-
lens instrument for measuring slight variations of the sun's diameter
by photography, utilizing the common chord of two overlapping
images.
Pho`to*he`li*om"e*ter (?), n.
[Photo- + heliometer.] (Astron.) A double-
lens instrument for measuring slight variations of the sun's diameter
by photography, utilizing the common chord of two overlapping
images.