ON COMETS. 129 



ing its own independent orbit, and each reflecting to the 

 eye its quota of the solar hght* 



(44.) A very striking feature in Professor Bond's en- 

 gravings, which he describes as frequently and certainly 

 observed in America, and which did not pass wholly 

 unnoticed in Europe, consists in the appearance of one, 

 and on some nights two, excessively faint, narrow, and 

 perfectly straight rays of li^ht, or *' secondary tails,'^ start- 

 ing off from the main tail on its preceding or anterior 

 side (that towards which the comet was advancing, and 

 which side was always the brightest, sharpest, and best 

 defined) in the direction of tangents to its curvature 

 at points very near the head, and extending on some 

 nights (on the 4th, 5th, and 6th of October) to a much 

 greater length than the primary or more luminous tail. 

 These appearances were presented from the 28th Sep- 

 tember to the nth of October with more or less dis- 

 tinctness. They are peculiarly instructive, as they clearly 

 indicate an analysis of the cojuetic matter by the sims 7'epul- 

 sive action the matter of the secondary tails being 

 evidently darted off with incomparably greater velocity 

 (indicating an incomparably greater intensity of repulsive 

 energy) than that which went to form the primary one. 

 The primary tail also presented another feature, fre- 

 quently, indeed almost always, observed in comets, viz., 



* Some anomalous appearances in the early development of the 

 tail in this comet, which was slightly curved, even when the earth 

 was in the plane of the orbit, can by no means be regarded as 

 fatal to this explanation of the general phcenomenon, as they might 

 have originated in a lateral direction of projection of the caudal 

 matter from the nucleus in ipso motiis initio. 



I 



