[f. ACTINO- + γράφ-ος writing. Cf. Gr. ἀκτῑνογραφία.] An instrument, invented by Sir J. Herschel in 1838, for recording the variations in the power of the solar rays.
1840. Sir J. Herschel, Phil. Trans., I. 46. Description of an Actinograph, or self-registering Photometer for meteorological purposes.
1853. R. Hunt, Man. Photog., 154. The instrument constructed by Sir John Herschel, which he has named an actinograph, not only registers the direct effect of solar chemical radiation, but also the amount of general actinic power in the visible hemisphere.
