RT Journal Article SR Electronic T1 Speculations upon a possible method of determining the distance of certain variably colored stars JF American Journal of Science JO Am J Sci FD American Journal of Science SP 190 OP 192 DO 10.2475/ajs.s2-40.119.190 VO s2-40 IS 119 A1 Joseph Wharton YR 1865 UL http://www.ajsonline.org/content/s2-40/119/190.abstract AB