48 MATTHEW FONTAINE MAURY 



alone responsible for the accuracy of the work as nothing 

 had been published until it had passed his supervision 

 and approval. 



A very ambitious work which Maury began during the 

 year 1845 was a catalogue of the stars. The aim was to 

 cover every point of space in the visible heavens with 

 telescopes, get the position of every star, cluster, and 

 nebula, and record both magnitude and color, with the 

 angle of position and the distance of binary stars to- 

 gether with descriptions and drawings of all clusters and 

 nebula^. No astronomical work on such an extensive 

 scale had ever before been executed or even attempted, 

 though the value and importance of it were manifold 

 and difficult of full estimation. Maury wrote that it 

 was his intention to make a contribution to astronomy 

 that would be worthy of the nation and the age, and to 

 so execute the undertaking that future astronomers 

 would value it so highly as to say that such a star was 

 not visible in the heavens at the date of the Washington 

 Catalogue because it is not recorded therein. 



An interesting example of the extremely practical 

 value of such a catalogue came up in connection with 

 Leverrier's discovery of the planet Neptune. In the 

 autumn of 1846, after the discovery of this planet, 

 Maury ordered one of his observers to trace its path 

 backwards to see if some astronomer had observed it 

 and entered it as a fixed star. On February 1, 1847, the 

 observer, Sears Cook Walker, gave a list of fourteen 

 stars from Lalande's catalogue in his ''Histoire Celeste", 

 where Neptune should have been approximately in May, 

 1795. Professor Hubbard was then directed by Maury 

 to examine with the equatorial, and he found on the 

 night of February 4 that the suspected star was missing. 



