GRAVITATION. 77 



These disturbances are, however, though great in num- 

 ber, much less in amount than we should suppose by 

 looking at astronomical diagrams. The reason is, that 

 the relative magnitudes and distances of these bodies are 

 very incorrectly represented in these diagrams. If the 

 sun is represented by a ball 75 feet in diameter, the earth 

 would be at the distance of a mile and a half, and would 

 be about the size of a man's head, and the next planet 

 beyond the earth would be three quarters of a mile far- 

 ther, and about half as large. It is impossible to repre- 

 sent these proportions on paper of a moderate size, and 

 accordingly, in all diagrams the sun and planets are 

 brought much nearer to each other in proportion to their 

 size, than they are in reality. It will be evident, from a 

 slight consideration of the true proportions, that the influ- 

 ence of the planets upon each other must be very incon- 

 siderable compared with that which is exerted upon them by 

 the immense body which occupies the centre of the system. 



2. GRAVITATION BETWEEN ONE HEAVENLY BODY AND 

 THE PARTS OP ANOTHEIl. 



If the facts stated under the preceding head were all 

 which had been observed, gravitation would not be pioved 

 to be a universal laic of matter. It would be doubtful 

 whether the attraction which causes two heavenly bodies 

 to approach, was a property belonging to every particle 

 of which each was composed, or whether it pertained 

 exclusively to some substance which each contained, but 

 which formed only a part of each. It might not have 

 been an improbable supposition that some central mass in 

 each might alone possess the attracting power, and cause 

 the bodies to which they respectively belonged, to ap- 

 proach each other. This supposition is, however, pre- 

 vented by the following facts. 



The Parts of the earth gravitate towards the heavenly, 

 bodies. The waters of the ocean and the atmosphere, 

 the only bodies connected with the earth which are ca> 

 pable of separate motion, have a motion separate from 

 that of the whole body of the earth. These waters, and 

 this atmosphere rise towards the sun and the moon on 



VOL. I NO. IV. 7* 



