ABSTRACT

Fig. 3.1 James Challis (1803-82) Director of the Cambridge Observatory, 1836-61 and Plumian professor until 1882, he was appreciated by contemporaries for his many observations with the Northumberland refractor, and as an inventor of instruments. He participated in a plan to gain the observational discovery of Neptune in 1846, attempting to do so personally, though some lack of initiative combined with his devotion to the daily work lost that opportunity for Cambridge.