212 Outlines of Meteoric Astronomy. 



was advocated in succession by Olbers, Laplace, Poisson, Biot, 

 and others. Lichtenberg was also of the same opinion, and 

 as late as the year 1839, Benzenberg affirmed that shooting- 

 stars migrated from the moon. He quoted Lichtenberg's remark, 

 that " the moon was a bad neighbour to the earth, and pelted 

 her with stones/' Laplace and Poisson, however, abandoned 

 this explanation on the ground that no projectile forces exist 

 upon the earth or moon sufficient to eject the stones with 

 planetary velocity. The native source and origin of fire-balls, 

 shooting-stars, and aerolites, still remained to be discovered; 

 and some advance in this direction was shortly afterwards 

 effected by an extraordinary occurrence in America. On the 

 morning of the loth November, 1833, there was witnessed in 

 the United States of America such a surpassing shower of 

 luminous meteors that every description of the display appears 

 to have fallen short of the reality. One fact, however, 

 remained certain, that a perfectly similar shower to this was 

 observed by Humboldt in Cumana on the morning of 

 the 13th November, 1799; and another, that the meteors 

 streamed outwards on all sides from the direction of a fixed point 

 near the star Gamma Leonis, during the continuance of the 

 shower. These two particulars Arago, the late French astro- 

 nomer, declared to be decisive in favour of a new theory for 

 the origin of luminous meteors. " They are/'' he said, " a 

 new planetary world, beginning to be revealed to us •/' they 

 circulate like planets round the sun. Shooting- stars obey the 

 Newtonian law of gravitation, and their orbits may be calcu- 

 lated like those of the planets or the'moon. It is now a fact 

 well proved by evidence that the November meteors return in 

 their greatest magnificence every thirty-three years, so that 

 their next central conjunction with the earth will take place on 

 the 13th or 14th November, 1866. 



(5.) Another date for periodical meteors, namely the 10th 

 of August, was shortly afterwards discovered by M. Quetelet 

 at Brussels, in 1836, and at this epoch may properly be said 

 to commence the period of prediction. M. Quetelet predicted 

 the return of this shower on the following 10th August, 1837, 

 ;md the prediction was fully confirmed, and has not failed since 

 to be verified in Brussels every succeeding year. M. Quetelet, 

 moreover, prepared Catalogues of Star-showers in 1839 and 

 1841, and specified particular dates for their return, all of which, 

 as will presently be shown, have since been verified. Of these 

 showers, the meteors of the 10th of August, although not the 

 brightest, are the most regular in their return. They appear 

 to fail every eighth year, the last minimum having taken 

 place in 1862 ; but the display of August 10th, 1863, is pro- 

 bably the brightest star-shower that has been witnessed in 



