John Crouch Adams 127 



The delay was decisive, for, on the 18th of September, 

 Leverrier, who had apparently no telescope of sufficient 

 power at his command, wrote to Galle, an assistant at 

 the Berlin Observatory, and the search was commenced 

 on the 23rd. Star charts were at the time being prepared 

 under the auspices of the Berlin Academy of Sciences, and 

 one of them covered the critical region. The same night a 

 star was discovered which was not registered in the map, 

 and the following night its change of position proved that 

 it was the looked for planet. It was afterwards found that 

 Challis, in his sweeps, had observed the planet on the 4th of 

 August, but not having compared his observations with those 

 made subsequently, had failed to recognize it as a moving 

 object. Had he done so, the first discovery of Neptune would 

 have fallen to the credit of Cambridge. The relative merits 

 of Adams and Leverrier were warmly discussed, but history 

 quickly disposes of all such questions of priority. Whether 

 of two discoverers one is a few weeks ahead of, or behind, 

 the other, seems all important at the time, but very soon 

 the adjudgment of merit turns upon the manner in which 

 the work was carried out rather than on the calendar. 

 Nevertheless, when so much seemed to depend on being the 

 first in the field, the disappointment of a young man standing 

 on the threshold of his career must have been severe, and 

 we cannot absolve either Airy or Challis from blame. 



Adams' subsequent work was unostentatious, but always 

 sound and thorough. We may note his investigations on 

 the secular acceleration of the moon's mean motion and on 

 the orbit of the swarm of meteors known as the Leonides. 



After 1844 a series of eminent men passed in rapid 

 succession through the Mathematical Tripos. William 

 Thomson (Lord Kelvin) graduated in 1845, and- P. G. Tait 

 in 1848, but their period of activity is associated with 

 Glasgow and Edinburgh rather than with Cambridge. Edward 

 John Routh (1831-1907) was born at Quebec and took his 

 degree as senior wrangler in 1854. For many years he held 

 a unique position as a teacher in his University, and it may 

 be said that the Mathematical Tripos in its best days owed 

 much of its success to Routh. Such, at any rate, is the 

 testimony of many distinguished men to whose work this 



