iG6 Periodic Meteors, or supposed Asleroids I [Jan. 



bring the two bodies together at intervals of a year*), several consi- 

 derations induced the belief, that half a year was the true period, an 

 inference drawn especially from the apparent great excess of velocity 

 of the earth at the point of concourse; but the period of a year (or, 

 more probably, a little less than a year), by implying that the two 

 bodies are always comparatively near to each other, would better ex- 

 plain the occurrence of shooting stars at all seasons of the year, and 

 would be particularly favourable to the explanation of those meteoric 

 showers which have on two occasions at least,t occurred near the last 

 of April, a time distant about half a year from November, and there- 

 fore sustaining a like relation to the opposite point of its orbit. In 

 such a case, meteoric showers would occur in April and November, 

 for the same reason that the transits of Mercury take place in May 

 and November exclusively. The greater frequency of meteors in 

 November than in April, naturally results from the greater proximity 

 of the earth to the sun at the former than at the latter period; to 

 which, perhaps, may be added the effect of the eccentricity of the orbit 

 of the meteoric body, the aphelion being on the side of November , 

 In the present state of our knowledge on this subject, I regard it as a 

 point open for inquiry, whether it will best accord with all the 

 phenomena of shooting stars, to give to the meteoric body a period of 

 nearly one year, or of half a year. 



I have been somewhat disappointed that the astronomers should 

 have paid so little attention to the remarkable changes which take 

 place in the zodiacal light about the 13th of November, as has been 

 repeatedly mentioned in this Journal. It appears to me a fact deserv- 

 ing their attention, that the zodiacal light, which for weeks before the 

 13th of November appears in the morning sky, with a western elonga_ 

 tion of from 60 to 90 degrees from the sun (while up to that time not a 

 glimpse of it can be caught in the evening sky), should immediately 

 afterwards appear after the evening twilight in the west, and rapidly 

 rise through the constellations, Capricornus and Aquarius, to an elon- 

 gation of more than 90 degrees eastward of the sun, while it as rapidly 

 vrithdrawR itself from the morning sk}^, and within a few days vanishes 

 rntirely from the western side of the sun. For three years past I have 

 observed these changes with much interest, and feel warranted in 



* See vol. xxvi. p. 166, of this Journal. 



t In Virginia, and various other parts of the United States, in 1803, and in France in 109» 

 making suitable allowances for the more rapid progress of the earth through the winter 

 signs, and for the change of style, and the meteoric shower of the 20th of April lc95, oe- 

 blurred at very nearly the very opposite point of the earth's orbit. 



