MIKACLES AND SPECIAL PEOVIDENCES. 27 



Well, Newton slowly marshalled his thoughts, or rather 

 they came to him while he ' intended his mind,' rising 

 like a series of intellectual births out of chaos. He 

 made this idea of attraction his own. But, to apply 

 the idea to the solar system, it was necessary to know 

 the magnitude of the attraction, and the law of its varia- 

 tion with the distance. His conceptions first of all 

 passed from the action of the earth as a whole, to that 

 of its constituent particles. And persistent thought 

 brought more and more clearly out the final conclusion, 

 that every particle of matter attracts every other particle 

 with a force varying inversely as the square of the dis- 

 tance between the particles. 



Here we have the flower and outcome of Newton's 

 induction ; and how to verify it, or to disprove it, was 

 the next question. The first step of the philosopher in 

 this direction was to prove, mathematically, that if this 

 law of attraction be the true one ; if the earth be 

 constituted of particles which obey this law ; then the 

 action of a sphere equal to the earth in size on a body 

 outside of it, is the same as that which would be 

 exerted if the whole mass of the sphere were contracted 

 to a point at its centre. Practically speaking, then, 

 the centre of the earth is the point from which distances 

 must be measured to bodies attracted by the earth. 



From experiments executed before his time, 

 Newton knew the amount of the earth's attraction at 

 the earth's surface, or at a distance of 4,000 miles from 

 its centre. His object now was to measure the attrac- 

 tion at a greater distance, and thus to determine the 

 law of its diminution. But how was he to find a body 

 at a sufficient distance ? He had no balloon ? and even 

 if he had, he knew that any height to which he could 

 attain would be too small to enable him to solve his 

 problem. What did he do? He fixed his thoughts 



