128 SCIENCE AND THE HUMAN MIND 



in London were revived, and in 1662 the society was 

 formally incorporated by charter of Charles II. as the 

 Royal Society of London for Promoting Natural 

 Knowledge. In France the corresponding Academic 

 des Sciences was founded by Louis XIV. in 1666, and 

 similar institutions soon appeared in other countries. 

 Their influence in focussing scientific opinion, and 

 making known the researches of their members, has 

 had much to do with the more rapid growth of science 

 since their foundation. 



Isaac Newton (1642-1727), by universal consent 

 the greatest man of science of all time, the delicate, 

 posthumous and only child of a yeoman, 

 was born at Woolsthorpe in Lincolnshire, 

 and educated at Grantham Grammar School and at 

 Trinity College, Cambridge, where he was greatly influ- 

 enced by the work of Descartes. About 1666, driven 

 to Woolsthorpe by an outbreak of plague at Cam- 

 bridge, he turned his attention to planetary problems. 

 Galileo's researches had shown the need of a force to 

 keep the planets in their orbits and prevent them 

 moving off in a straight line. The Dutch physicist 

 Huygens had calculated the intensity of the force 

 needed to keep a body whirling in a circular orbit with 

 a known velocity. It remained to show that such a 

 force existed in the case of the moon and the planets. 



Newton is said to have grasped the clue while idly 

 watching the fall of an apple in the orchard at Wools- 

 thorpe. If the earth pulled the apple, would it not 

 also pull the moon ; and would not the sun by a 

 similar force pull the planets round in their orbits ? 

 The distance of the moon is 60 radii of the earth, so 



