ED. PICKERING. — Photometric observations (Observations photométriques); Annales de l'Observatoire d'Harvard College, t. IX, p. 1; 1880 C. FabreJ. Phys. Theor. Appl., 9 1 (1880) 418-420DOI: https://doi.org/10.1051/jphystap:018800090041802