19. Mathematical and Astronomy Notes & Postcards

One-cent postcard to “Prof. G.W. Coakley, Hempstead, Long Island” stamped January 25 1890 from “Packer Institute” and dated January 24, 1890. One-cent postcard to “G.W. Coakley, University of the City of New York, N.Y.” from the American Astronomical Society sent from its secretary, Garrett P. Serviss, from Brooklyn, January 27th, 1886. Mathematical and astronomy notes.