Dreyer's first catalogue: the supplement to Herschel's General Catalogue

Dreyer's first catalogue, titled ‘A supplement to Sir John Herschel's ‘General Catalogue of Nebulae and Clusters of Stars’, appeared in March 1878 in the Transactions of the Royal Irish Academy (Dreyer 1878a). The work – henceforth abbreviated GCS – had already been received by the Academy on 26 February 1877, but afterwards was corrected by the author. Besides the new objects, it contains a large number of notes and corrections to Herschel's GC. At the same time Dreyer was working on the compilation of the Birr Castle observations made during 1848–78. These two projects influenced each other. In the GCS all objects newly found at Birr Castle were entered with calculated coordinates. The same applies for discoveries of other observers, such as Schultz and Tempel. Dreyer's supplement was the essential step towards the NGC. His first appearance as author of an important catalogue of nebulae and star clusters gives us the occasion for a detailed review of his life. DREYER'S BIOGRAPHY Copenhagen Johan Ludvig Emil Dreyer (in English later: John Louis Emil) was born on 13 February 1852 in Copenhagen (Fig. 8.1). Many of his ancestors served in the army and navy. His father, Johan Christopher Friedrich Dreyer, became Danish Minister of War and the Navy in 1864.