HUMBOLDT AND BOXPLAND. 



may be observed as signals for determining differences of longi- 

 tude by simultaneous observations, and Maskelyne in 1783 

 published a paper on the subject, in which he calls the attention 

 of astronomers to the phenomena, and distinctly points out 

 this application. The idea was revived by Benzenberg in 1802, 

 but so long as they were regarded merely as casual phenomena, 

 it could scarcely be hoped that they would be of much use in 

 this respect to practical astronomy. As soon, however, as their 

 periodicity became probable, the phenomena acquired a new in- 

 terest, and some recent attempts to determine longitudes in this 

 manner have proved that the method is not to be disregarded. 



The probability of the conjecture that the causes of the meteoric 

 phenomena observed in the months of August and November is 

 to be found in the fact that the particular regions of the solar 

 system through which the earth passes at these seasons, are the 

 seats of an unusual quantity of the matter composing these 

 meteors, must in a great degree depend on the extent to which 

 it can be proved by observation that such meteors do really 

 prevail at each of those periods of the year. 



16. With a view of testing this, we have collected together, from 

 various sources, the dates of the most remarkable atmospheric 

 appearances of this class from the eighth century to the present 

 time. In the table in the following page, the day of the month 

 when it has been recorded, is placed in the column under the 

 month, and in the line with the year of the occurrence. Where 

 an asterisk occurs under the month, the particular night has 

 not been recorded, but the appearance has merely been mentioned 

 as having occurred. 



17. There are here recorded fifty-two nights on which these ap- 

 pearances prevail to such a degree as to attract particular notice. 

 Of these, twenty-six occurred between the 8th and 15th of 

 August, and thirteen the 6th and 19th of November. Thus three- 

 fourths of the nights recorded correspond to the epochs to which 

 we have referred. 



Some disappointment was produced in 1837, by the circum- 

 stance of an unusually small number being seen on the night 

 between the 12th and 13th, arising from an erroneous impression 

 that that was the night on which their periodical return should 

 be expected. It will be seen, however, from the preceding table, 

 that these appearances have not at all been confined to the night 

 of the 12th ; but independently of this, the night of the 12th at 

 Paris was so bright, that stars of the second magnitude were not 

 visible, and consequently meteors even supposing them to have 

 existed of similar or of inferior brightness could not have been 

 observed. It should also be considered, that their non-appearance 



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