MIRACLES AND SPECIAL PROVIDENCES. 03 



then, the centre of the earth is the point from which 

 distances must be measured to bodies attracted by the 

 earth. This was the first-fruit of his deduction. 



From experiments executed before his time, Newton 

 knew the amount of the earth's attraction at the earth's sur- 

 face, or at a distance of 4,000 miles from its centre. His 

 object now was to measure the attraction at a greater dis- 

 tance, 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 had, he knew that any height 

 which he could attain would be too small to enable him to 

 solve his problem. What did he do ? He fixed his thoughts 

 upon the moon — a body at a distance of 240,000 miles, or 

 sixty times the earth's radius from the earth's centre. He 

 virtually weighed the moon, and found that weight to be 

 g-uVfth °f what it would be at the earth's surface. This is 

 exactly what his theory required. I will not dwell here upon 

 the pause of Newton after his first calculations, or speak of 

 his self-denial in withholding them, because they did not 

 quite agree with the observations then at his command. 

 Newton's action in this matter is the normal action of the 

 scientific mind. If it were otherwise — if scientific men were 

 not accustomed to demand verification — if they were satis- 

 fied Avith the imperfect while the perfect is attainable, their 

 science, instead of being, as it is, a fortress of adamant, 

 would be a house of clay, ill-fitted to bear the buffetings of 

 the theologic storms to which it has been from time to time, 

 and is at present exposed. 



Thus, we see, that Newton, like Torricelli, first pondered 

 his facts, illuminated them with persistent thought, and 

 finally divined the character of the force of gravitation. But 

 having thus travelled inward to the principle, he had to re- 

 verse his steps, carry the principle outward, and justify it 

 by demonstrating its fitness to external Nature. This he 

 did by determining the attraction of the earth and moon. 



