[This was Mr. Lockyer’s note. In point of fact, the Author was responsible for the verbatim paragraphs comprised between the letters _A_ and _B_, and _C_ and _D_, in the instructions as now reprinted.] [18] Communicated by the author to the Royal Saxon Academy of Science, 1871. [19] Reports of the Royal Saxon Academy of Science, Oct. 31, 1871. [20] This red line was first noticed by Zöllner. [21] Recherches sur le Spectre Solaire, p. 42. [22] American Journal of Science, lxviii. 123. End of the Project Gutenberg EBook of Auroræ: Their Characters and Spectra, by J. Rand Capron