[John Louis Emil]. Danish astronomer, born in 1852 at Copenhagen. M.A. and Ph.D. of Copenhagen University. He was astronomer at the Earl of Rosse’s Observatory, Birr Castle, 1874; assistant astronomer at the Observatory of Trinity College, Dublin, 1878; director of Armagh Observatory, 1882; and was the author of Second Armagh Catalogue of 3,300 Stars for 1875, from Observations Made in the Years 1869–83 (1886); A New General Catalogue of Nebulæ and Clusters of Stars (1888); Tycho Brahe: A Picture of Scientific Life and Work in the Sixteenth Century (1890); and various papers on astronomical and other scientific subjects.
