GRAVITATION. 03 



of a water-wheel of his own construction, often occupied 

 his attention when the sheep were astray, and the corn 

 was treading down by the cattle.' This was wrong. No 

 interest in science, or desire for intellectual improve* 

 ment, can excuse neglect of duty, and especially any un- 

 faithfulness to a trust reposed by a parent. 



Not long after this, Newton, at the age of eighteen, en- 

 tered the University at Cambridge. Here he soon became 

 distinguished for his interest and progress in mathematical 

 science, and soon after receiving his degree, he turned 

 his attention to some experiments upon light and colors^ 

 which, however, we must not stop to describe. The 

 plague soon after broke out at Cambridge, and to avoid 

 it, he retired to his former home. Here he spent two 

 years, and during this period of retirement and seclusion, 

 he made the discoveries in regard to gravitation, which 

 have immortalized his name. One day, when he wa 

 seated alone in a garden, the fall of an apple arrest- 

 ed his attention. Why should it go towards the earth? 

 was the question. A common mind would have been 

 satisfied with saying, that the support of the stem was 

 removed, and that it fell of course. This, however, did 

 not satisfy our philosopher. He reflected on the subject 

 long. It was not that the fall of the apple appeared new 

 to him. It was only the occasion, which led his mind to 

 reflect on this universal tendency towards the earth, with 

 which, as a fact, he had long been familiar. He consid- 

 ered, that this tendency towards the earth, was the same 

 in all parts of the earth, and at all places. It was not 

 sensibly increased or diminished, in deep valleys or on 

 lofty mountains. It occurred to him that the power 

 might perhaps extend far from the earth, into the regions 

 of the air. It might possibly affect the moon, and if so, 

 if it should prove that the moon was constaatly under 

 the influence of an attraction towards the earth, the 

 nature of her motion in an orbit would be at once explain- 

 ed, and all, the cumbrous perplexities of former philoso- 

 phers, to account for the celestial revolutions would be 

 ended at once. ' I will make the calculation,' thought 

 he, ' and ascertain whether the motions of the moon cor- 

 respond with such a supposition.' 



