214 CELESTIAL MEASURINGS AND WEIGHINGS. 



(41.) Shall we spread our wings for a farther flight to 

 the region of the nebulae ? For such an excursion we are 

 hardly yet prepared. Our present reach extends, as we 

 have seen, only to a very few of our nearest neighbours 

 among the stars ; a class of bodies which we have every 

 reason to believe form with our own sun a system to us 

 a universe but which, removed to the distance of the 

 nebulae, would appear perhaps as one of them. More- 

 over, it is not wings, but a resting-place for the sole of 

 our foot that we want. If we knew in what orbit the sun 

 itself is moving (for that it moves is certain, and with no 

 trifling speed), and if human observations were to endure 

 till it had completed half a circuit in that vast orbit then 

 indeed we should have established a new base line from 

 whose extremities the parallax of the nearest nebula 

 might become sensible. Failing this, we must rest con- 

 tent with such probable indications as we can glean from 

 other sources. 



(42.) There is one which can hardly fail to strike any 

 one who does not reject altogether from his philosophy 

 the consideration of design and purpose in the construc- 

 tion of the frame of nature. In their orbits round the 

 sun, the earth and other planets carry round with them 

 satellites retained in their orbits by gravitation to their 

 primaries. These orbits, though very sensibly disturbed 

 by the sun's attraction, are yet in no case so much so as 

 to hazard in the smallest degree the stability of these 

 miniature planetary systems, or in the lapse of even in- 

 definite ages to produce any very material change in 

 their relations to their primaries or to each other. The 



