iv PURSUIT OF KNOWLEDGE 59 



named William Thomson), one of the examiners remarked 

 to another, " You and I are just about fit to mend his 

 pens." His genius was recognised, but the examination 

 did not provide a way of showing it. 



To be able to observe details and distinguish minute 

 resemblances and differences are attributes of every 

 scientific observer. In 1781 Sir William Herschel was 

 " searching the skies " when he noticed that one star 

 " appeared visibly larger than the rest." He came to 

 the conclusion, after making several observations, that 

 this object was not a star but a comet. Further studies 

 of the body and its movements proved it to be a new 

 planet the first to be discovered in historic time. The 

 other planets, Mercury, Venus, Mars, Jupiter and Saturn 

 have been known back to the earliest days of the human 

 race of which written records exist ; and the discovery 

 of this new planet, to which the name of Uranus was 

 given, revolving round the sun with the rest, but pre- 

 viously unrecognised, aroused great interest. Other 

 astronomers had examined at various times the parts 

 of the sky occupied by Uranus, but they did not notice 

 any difference of appearance between it and an ordinary 

 star. By overlooking nothing in his field of view, 

 Herschel became the discoverer of a world which proved 

 to be nearly fifty times larger than the globe on which 

 we live. 



Herschel scrutinised everything ; and this all-seeing 

 eye, combined with sagacity of interpretation, is char- 

 acteristic of all great observers. Of Charles Darwin it 

 is recorded : 



He wished to learn as much as possible from an experiment, 

 so that he did not confine himself to observing the single point to 

 which the experiment was directed, and his power of seeing a 

 number of other things was wonderful. There was one quality 



