GRAVITATION. 95 



studies, arid became sometimes involved in controversies 

 in defence of his opinions. These he much regretted, 

 for he was of a mild and peaceable disposition. His 

 character was marked with almost all that is excellent. 

 There were no eccentricities cherished, no singulari- 

 ties in manners or opinions ; he was kind to others, 

 modest and unassuming in regard to himself ; he de- 

 pended on patient, persevering effort for his success in all 

 his efforts, and by his constant fidelity, in the discharge 

 of the duties of social life and religion, he seemed to aim 

 more at happiness, than at fame. 



QUESTIONS. 



What is the law of gravitation 1 



Is the truth of this to be proved by theoretical reason- 

 ing, or by the observation of facts ? 



What is the first class of facts named 1 



Has it always been known that the revolutions of the 

 planets were caused by the attraction of the central body ? 



Is there any other evidence of attraction between ce- 

 lestial bodies, besides the attraction of the sun for the 

 planets 1 



What effect is produced by the attraction of the plan- 

 ets for each other 1 



Are these disturbances of the regular motions nume- 

 rous ? Are they great? 



What is the second case in which the operation of 

 gravitation is pointed out? 



What parts of the earth are capable of a separate mo- 

 tion towards the sun and moon 1 



What is the third class of facts named 1 



How is the attractive force of a mountain made evi- 

 dent? 



Upon what mountain was the experiment first tried ? 

 Was the effect perceptible? 



Upon what other mountain has the experiment been 

 made! 



Were the effects produced very great? How much 

 did the plumb line deviate? 



Is there any other way in which gravitation has been 

 made apparent? 



