METEORS AND AEEOLITES. 305 



from 2 to 3 o'clock in the morning 7*1 from 5 to 6 o'clock 

 8-2. And this gradation is maintained also in the case of 

 the meteors of periodical recurrence. 



Equally remarkable is the result as to the monthly or 

 annual variations of these phenomena. A laborious reduction 

 of observations has furnished a table expressing the monthly 

 mean of the horary number at midnight. This table shows 

 a singular disparity between the first six months of the year 

 and the last; the mean number of shooting-stars in the 

 former being only 3*4 in the hour, in the latter rising as 

 high as 8 ; that is, a smaller number when the earth is 

 moving from perihelion to aphelion, or receding from the 

 sun a much greater number in the other six months, when 

 it is advancing towards its perihelion. The transition is rapid 

 from one of these conditions to the other. In December the 

 mean number in the hour is 7*2 in January only 3*6. In 

 June 3*2 in July 7*0. It is well worthy of note that the 

 two maxima in the table occur in August and November ; 

 thus according exactly in date with the periodical showers 

 we have described ; and with the further concurrence of fact 

 that these maxima are not present every year. In 1842 the 

 mean for August was 11-9 in 1844 only 5-4. In 1842 the 

 mean for November was 11*3 in 1843 it was 5*4. 



Another section of the enquiry before us regards the 

 direction of these shooting-stars. Without entering into the 

 details, we may remark the general conclusion that almost 

 exactly the same number come from the north and south 

 conjointly, as from the east and west; but with this diversity, 

 that, while the number is nearly the same from north and 

 south, the number coming from the east much more than 

 doubles that from the west. The amount of the diversity, 

 however, differs in different years. This copious accumu- 

 lation of facts afforded other curious results as to the length 

 of the visible trajectories, the position of the centre of the 



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