382 Miscellanies. 



the true cause. The estimate formed at the same time of the velo^ 

 city of the meteors, required correction in a shiiilar manner; for it 

 proceeded on the hypothesis that the velocity was merely that which 

 was generated by falling, by the force of gravity, from the height of 

 two thousand two hundred and thirty eight miles; whereas, an in- 

 sio-ht into the real cause of the phenomenon, showed at once that a 

 great relative velocity was to be added to that of gravity. The es- 

 timated motion of the body being 12.15 miles per second, and that 

 of the earth about 19 miles, a relative velocity was to be reckoned of 

 6.85, to which if we should add any thing within the possible force 

 of gravity, which is about seven miles per second, we may have a 

 velocity corresponding nearly to that which, according to Mr. Twi- 

 ning, the meteors were observed' to have, allowing much latitude 

 for the uncertainties of observation, where fractions of a second are 

 involved, and the observer guesses at the time. 



3. It is said that meteors occur at other seasons of the year, and 

 more or less at all seasons, for which this theory does not account. 



According to the theory, the earth forms with the nebulous body, 

 during the year, three inferior conjunctions, — one In November, one 

 in January, and one In September, in each of which positions it would 

 be favorably situated for parting with some of its "extreme portions" 

 to the earth- Moreover, a light body moving in "the contemplated 

 orbit, would be subject, no doubt, to very great perturbations, such 

 as to shift the places of its nodes and conjunctions, to a greater or 

 less extent, at every revolution. We can conceive of one position ot 

 the nodes, which would be extremely favorable for producing such 

 a phenomenon as that of Nov. 13, 1833, namely, when the line of 

 the nodes coincides with that of the apsides. 



It has been erroneously supposed essential to my theory, that the 

 meteoric shower should return every 13th of November, and that 

 the merits of the theory were staked on the return of the phenomenon 

 in November, 1834. I have much less honor to claim, on the score 

 of predictions, than some have been pleased to ascribe to me. It did, 

 indeed, seem to me probable, that the remarkable combination of cir- 

 cumstances, which caused the shower of meteors to appear as early 

 as 1831 ; to be repeated, to a greater extent, In 1832; and to arrive 

 at such an unexampled degree in 1833, would continue somewhat 

 longer, and that the showers would go off as they came on- Hence, 

 I intimated to my pupils, the possibility of a recurrence on the 

 morning of Nov. 13, 1834, and to a greater or less extent for a 



