ASTRONOMY AND METEOROLOGY. 



371 



PERIODIC METEORS IN 1849. 



M. COULVIER GRAVIER, in a paper presented to the French Acade- 

 my on Dec. 10, 1849, states that his observations upon the meteors of 

 the 12th and 13th of November do not agree with Prof. Olmsted's 

 theory of their periodical Appearance and radiation. It is known that 

 these meteors, radiating from a point in the Lion, cannot appear before 

 the rising of that constellation, and Prof. Olmsted affirms that no 

 shooting star shows itself before midnight, when some large meteor 

 seems to give the signal for their periodical appearance. M. Gravier's 

 own observations have shown this not to be the case, and his view has 

 been confirmed by observations made at Breslau, where numerous 

 meteors appeared before midnight, so that we must either deny the 

 radiation in question, or consider as strangers to the periodical return 

 the 88 meteors of the 12th of November, and the 69 of the following 

 day. "It is to be regretted that observations were not made in Sile- 

 sia before and after that period, for there would have been found an 

 increasing scale till the 16th of October, followed by a descending one 

 which has not yet ceased. The numbers observed at Breslau would, 

 doubtless, have been proportional to ours. We give here the means 

 of several days." 



Mean Dates. 



July 23, 

 " 24, 

 Aug. 7, 

 " 10, 

 " 14, 

 " 20, 

 Sept. 7, 

 15, 

 24, 



Hourly Mean. 

 8 stars. 



21 " 



tt 



tt 



55 

 106 



tt 

 (( 



60 

 21 

 20 

 20 

 15 



it 

 It 

 a 

 tt 

 it 



Mean Dates. 

 Oct. 8, 

 " 16, 

 " 21, 

 " 29, 

 Nov. 7, 

 14, 

 22, 

 5, 



a 



Dec. 



Hourly Mean. 

 30 stars. 

 40 

 31 

 25 

 16 

 13 

 12 

 21 



(C 



It 

 It 

 It 

 tl 

 tt 

 It 



It will thus be seen that the hourly numbers of the 12th and 13th 

 of November are smaller than those of any preceding day since July. 

 The observations for the preceding years furnish other proofs of the 

 change of the maximum of November. From a table given it appears 

 that the hourly number of shooting stars seen on the 12th and 13th of 

 November has gradually decreased from 100 in 1833 to 14 in 1848, 

 and 17 in 1849. The change has not, however, been wholly regular ; 

 thus in 1844 the number was 20 ; in 1845, 35 ; and in 1846, 13 ; but 

 yet on the whole there is an evident decrease since 1833. It will soon 

 be ascertained whether this decrease, continuing through seventeen 

 years, will be followed by an increase for the same period. 



PERIODIC METEORS FOR 1850. 



OBSERVATIONS made at different points during the past year show 

 that the meteors have again proved true to their established periods. 

 On the evening of the 9th of August, three observers at New Haven 

 counted in 2 hours (from 12h. 40m. to 3h.) 451 meteors. They 



