Mr Galloway on Shooting-Stars and Meteors. 391 



The second great meteoric epoch is the 10th of August, first 

 pointed out by M. Quetelet; and although no displays similar 

 to those of the November period have been witnessed on this 

 night, there are more instances of the recurrence of the phe- 

 nomena. In the last three years shooting-stars have been ob- 

 served in great numbers, both on the 9th and 10th ; but they 

 appear in general to be unusually abundant during the two 

 first weeks in August. The other periods which have been 

 indicated are the 18th of October, the 23d or 24th of April, 

 the 6th and 7th of December, from the 15th to the 30th of 

 June, and the 2d of January ; and it is not improbable that 

 further observations will add to the number. 



Theories- regarding the Origin and Phenomena of Shooting- 

 Stars. — The different theories which have been given to ex- 

 plain the origin and phenomena of the shooting-stars are next 

 stated. The following are the principal : — 



1. That the shooting-stars and fire-balls are substances 

 projected from volcanos in the moon. It is known that a 

 body projected vertically from the moon with a velocity of 

 about 8500 feet in a second would not fall back upon the lu- 

 nar surface, but would recede from it indefinitely ; and in or- 

 der to reach the earth the projectile would only require, un- 

 der the most favourable circumstances, to have a velocity of 

 about 8300 feet. Such a velocity, which is only about four 

 or five times greater than that of a cannon-ball, is quite con- 

 ceivable ; but the extraordinary exhibitions of 1799 and 1833, 

 to say nothing of their supposed periodicity, is utterly irre- 

 concilable with the theory of a lunar origin. Benzenberg, 

 however, adopts this theory, and supposes the shooting-stars 

 to be small masses of stone, from one to five feet in diameter, 

 which are projected from lunar volcanoes, and circulate about 

 the earth or about the sun when their projectile velocity ex- 

 ceeds a certain limit. 



2. Dr Olbcrs, and some other astronomers, have supposed 

 the shooting-stars to be the debris, or fragments of a large 

 planet, burst into pieces by some internal explosion, of which 

 Ceres, Pallas, Juno, and Vesta, are the principal remaining 

 portions. The smaller fragments continue to circulate about 

 the sun in orbits of great eccentricity, azid when they ap- 



