OF NATURAL PHILOSOPHY. 23 



every conclusion which cannot be made apparent to 

 our senses. Now, among these there are many so 

 very surprising, indeed apparently so extravagant, 

 that it is quite impossible for any enquiring mind 

 to rest contented with a mere hearsay statement of 

 them, we feel irresistibly impelled to enquire fur- 

 ther into their truth. What mere assertion will 

 make any man believe, that in one second of time, 

 in one beat of the pendulum of a clock, a ray of 

 light travels over 192,000 miles, and would there- 

 fore perform the tour of the world in about the 

 same time that it requires to wink with our eyelids, 

 and in much less than a swift runner occupies in 

 taking a single stride ? What mortal can be made 

 to believe, without demonstration, that the sun is 

 almost a million times larger than the earth ? and 

 that, although so remote from us, that a cannon ball 

 shot directly towards it, and maintaining its full 

 speed, would be twenty years in reaching it, it yet 

 affects the earth by its attraction in an inappreciable 

 instant of time? a closeness of union of which 

 we can form but a feeble, and totally inadequate, 

 idea, by comparing it to any material connec- 

 tion ; since the communication of an impulse to 

 such a distance, by any solid intermedium we are 

 acquainted with, would require, not moments, but 

 whole years. And when, with pain and difficulty 

 we have strained our imagination to conceive a dis- 

 tance so vast, a force so intense and penetrating, if 

 we are told that the one dwindles to an insensible 

 point, and the other is unfelt at the nearest of the 

 fixed stars, from the mere effect of their remoteness, 

 while, among those very stars are some whose actual 

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