IN THE SOLAR SYSTEM. 



85 



The doctrine of probabilities satisfies me that if a nebulous body did revolve round the 

 sun in the space within the earth's orbit, the chances of its performing its revolutions in 

 exactly half a year, and meeting the earth annually on the 13th of November, would be 

 precisely one to infinity. 



It is true the arcana of astronomy furnish us with some remarkable coincidences, not 

 only in the simple periods, but also in the grand cycles of the heavenly bodies. I shall 

 have occasion in the progress of this essay to point out one of these coincidences not hereto- 

 fore noticed, having an important bearing upon our subject, and which, in respect of ex- 

 actitude, is almost without a parallel in the annals of the science. But any hypothesis, 

 based upon an imaginary coincidence in period of bodies independent of each other, 

 staggers under a load which will certainly crush it. 



We have one more hypothesis to examine, that of the nebulous ring round the earth, 

 proposed by the Rev. George Jones, U. S. N. If an unprejudiced person, one who bad 

 the ability to reason in such matters, were asked what effect the sun's rays should have 

 upon a ring so placed, his reply would be, that matter placed in a circle round the earth 

 should have, in all its parts, optical relations, identical with those of the moon when occu- 

 pying corresponding positions. Thus, the part of the ring in opposition to the sun, should 

 shine with the greatest brightness; the parts in quadrature with the sun, with half the 

 brightness, &c. The brightest part should be nearest the zenith at midnight. The reve- 

 rend gentleman makes no mention of such an appearance. His observations, therefore, 

 do not conform to the requirements of his hypothesis. 



Von Humboldt, in commenting upon the Ilev. George Jones's paper, says he has ob- 

 served the same phenomenon, i. e,, the zodiacal light in the east, as well as in the west, 

 after sunset. He noticed that the two lights disappeared at the same time, and ascribed 

 the cause of the phenomenon in the east to reflection* 



I would fain believe that the objections I have urged to the hypotheses hitherto offered, 

 to explain the cause of this interesting phenomenon, do not apply to the theory here de- 

 duced from independent data. 



The form and position which the laws of perspective give to the ascending mass of ether, 

 conform to those which observation has given to the zodiacal light, even to the minute 

 point of the greater portion being north of the ecliptic. 



The changes in the velocity, &c.,of the many minor currents which make up the great 

 hollow cone, depending as they must, upon the varying conditions of the sun's surface, 

 explain the changes which the zodiacal light presents from day to day. 



* Cc 



nptcs Bendus, October 22, 1855. 



