METEOKIC STONES AND SHOOTING STARS. 



meteors. Arago lias suggested the probability of their periodical 

 recurrence between the 22ud and 2oth April. Humboldt thinks 

 that other annual periods may be assigned to the 6-1 2th De- 

 cember, and Capocci has assigned the 17th July, and the 27-29th 

 November as the dates also of their probable periodic occurrence. 

 On the night of the 6th December, Brandt observed and 

 counted 2000 shooting-stars; and on the llth December, 1836, 

 according to Humboldt, an immense fall of aerolites took place in 

 Brazil, near the village of Macao, on the banks of the river Assn. 



In the interval between 1809 and 1839, Capocci shows that 

 twelve falls of aerolites took place between the 27th and 29th 

 November, besides others oil the 13th November, 10th August, 

 and 17th July. 



On the whole, the following appear to be the dates at which 

 the recurrence of these meteors may be looked for : 

 22-25th April. 

 17th July. 

 10th August. 

 12-14th November. 

 27-29th November. 

 6-1 2th December. 



From all this it must be inferred that those parts of its annual 

 orbit through which the earth passes at these dates severally, 

 are intersected by the orbits of those groups of bodies, which, 

 when passing near the earth, present the appearance of shooting- 

 stars, or aerolites. 



22. From all that has been stated it may be considered then 

 as demonstrated w r ith the highest degree of probability, if not 

 with moral certainty, that the phenomena called shooting-stars, 

 fire-balls, and meteoric stones are identical ; that these latter 

 bodies belong not to the earth, but are masses of matter moving 

 like the planets in the celestial spaces, subject to the gravi- 

 tating attraction of the sun ; that the earth encounters them 

 occasionally, either striking directly upon them, or approaching 

 so close to them that they are drawn by the terrestrial attrac- 

 tion, first within the atmosphere, and afterwards to the surface ; 

 that the shooting-stars, which rush athwart the heavens without 

 falling on the earth, are the same class of bodies which do not 

 either directly strike the earth or come so close to it as to be 

 drawn to its surface by its attraction. 



Since it is supposed that these bodies become visible only 

 after they enter the atmosphere, being there rendered luminous 

 by the heat which they develop by the sudden and violent 

 compression of that fluid, it is probable that they may be 

 passing around us in countless numbers, outside the atmo- 

 166 



