16 Astronomy and Geology compared. PT. i. 



least so far as it relates to our own solar system, 

 such absolute certainty in calculating the magni- 

 tudes, the distances, the velocities, and the motions 

 of the different bodies composing the planetary 

 system ; we cannot conceive the possibility of error. 

 The novel and bold theories of Professor Stokes and 

 others, founded upon the results of the spectroscope 

 and calculations of the velocity of light, carry the 

 speculations of the astronomer beyond the bounds of 

 our own solar system, in an attempt to measure the 

 distance of the fixed stars, and to trace motion in 

 those bodies which hitherto were deemed stationary. 

 I will not attempt to follow those daring specula- 

 tions through those new fields on which they invite 

 us to enter. No doubt the enterprising energy of 

 those philosophers will explore these new regions of 

 science, should they prove accessible to the powers 

 of Man. I am contented for the purposes of this 

 essay to restrict myself within the bounds of our 

 own solar system, which has been so thoroughly 

 understood and established. Should it prove pos- 

 sible to future astronomers to extend our knowledge, 

 no new discovery lying altogether beyond the limits 

 of our own system can disturb the calculations we 

 have arrived at, or shake the truths which have 



