NOTES 



ON VARIOUS SCIENCES, 



ASTRONOMY, &c. 



ASTRONOMY is a mixed mathematical science, 

 teaching the knowledge of the celestial bodies, 

 their magnitudes, motions, distances, periods, 

 eclipses, and order. 



Celestial Objects seen where they are not. 



Notwithstanding the rapid motion of light, (1 70,000 

 miles per second,) it is evident that if a luminous 

 body were suddenly placed in the heavens, at. (for 

 example) the same distance as the sun is from us, 

 we could not possibly see it before the lapse of 8| 

 minutes. The consequence of this interval is, that 

 when we behold a celestial object, we do not see it 

 in the place where it actually is, but in the place 

 where it was some time before. 



Herschel thinks the light of some of his distant 

 nebulae (now visible with telescopes) would be 

 48,000 years in reaching us. 

 B 



