From the Robin Catalogue:
A. MS., G-1910-2, August 11-15, pp. 1-30 (with p. 5 missing); 6, 8-10 of another draft; and pp. 1-2 (“Notes to CSP’s Third Paper in the Pop. Sci. Monthly, 1878, March”). Published in entirety as 2.661-668 and as 2.645n1. Article III refers to the third in the Popular Science Monthly series of 1877-78.