129 



THE ASTEROIDS. 



BY n. KIEKWOOD, OF LANCASTER, PA. 



The first day of the present century is memorable in the annals of 

 astronomy for the discovery of the planet Ceres ; the first discovered of 

 those telescopic bodies to which the term Jlsteroids has been applied. 

 The smallness of its si«e, compared with that of the other planetary 

 bodies, induced Dr. Olbers to conjecture that it might possibly be the 

 fragment of a larger planet, which, at some remote period, had been vio- 

 lently disruptured. Tke subsequent discovery of Vesta, .luno, and Pal- 

 las, at nearly equal distances from the sun, was regarded as affording 

 strong presumptive evidence of the truth of his conjecture. It is stated, 

 moreover, in the last number of the "Record and Journal," that "the 

 orbit of Astraea, (the newly discovered Asteroid,) agrees with the sup- 

 position of a common point of re-union among the different fragments 

 of the larger planet from which these smaller ones have been supposed 

 to have been severed." This hypothesis has, in general, been favorably 

 .received by astronomers. In the list of its advocates may be found the 

 names of Brewster, Dick, Lardner, and many others of scarcely less 

 distinction in the scientific world. 1 propose to notice briefly some of 

 the considerations alledged for its support. 



1. It is said that the order discoverable in the distances of the plan- 

 ets from the sun, demands the existence of one planet between the or- 

 bits of Mars and Jupiter, at about the mean distances of the Asteroids. 



This relation was first observed, towards the close of the last cen- 

 tury, by M. Bode, of Berlin, who remarked that one of the term.s of the 

 progression was waning. He conjectured, therefore, that in this mter- 

 val there might possibly exist an undiscovered planet. According to 

 this astronomer, if 10 be assumed as the earth's distance from the sun, 

 the distances of the other planets may be expressed as follows : 



=4 



= 7 

 = 10 

 = 16 



= 28 

 = 52 

 = 100 

 = 196 



This series, it must be acknowledged, furnishes us with a remark- 

 able approximation" to the relative distances of the planets. It is, how- 

 ever, purely empirical. In other words, it cannot be shown to obtain 

 17 



