6 DISCOVERY CH. 



When the French astronomer and mathematician, 

 Lalande, was computing with Clairaut the disturbing 

 influences to which Halley's comet had been subjected, 

 he worked at the calculations during six months from 

 morning to night, and often at meal times ; and by his 

 devotion to this self-imposed task, contracted an illness 

 which changed his constitution for the rest of his life. 

 It was necessary to calculate the distance of each of the 

 two planets Jupiter and Saturn from the comet separately 

 for every degree over a period of one hundred and fifty 

 years. There was no mercenary motive under this 

 tremendous labour, but only the desire to define the 

 movements of an object which at intervals of about 

 seventy-six years had filled mankind with terror by its 

 appearance in the sky. 



Reward as the world understands it for work done 

 or results obtained, is the last thought of a student of 

 science. " I have no time to make money," was the 

 reply of the naturalist, Louis Agassiz, to an offer to lend 

 himself to a legitimate and tempting financial scheme. 

 Napoleon the Third once expressed surprise to Pasteur 

 that the great investigator did not endeavour to make 

 his discoveries and their applications a source of profit. 

 " In science," Pasteur replied, " men of science would 

 consider that they lowered themselves by doing so." 

 In a conversation with Lady Priestley, Pasteur 

 remarked, " I could never work for money, but I would 

 always work for science." If he had chosen to keep 

 his discoveries to himself, he could have been one of the 

 most wealthy men in the world, but he gave them to the 

 human race, and was content to end his career as a 

 professor of chemistry in receipt of a modest salary 

 from the Government of his country. 



Faraday on one occasion said to Tyndall that, at a 



