THE ORGUEIL METEOR. 357 



Prestwich, Ales- Herschel and Baden Powell. Every year it publishes a pro- 

 gramme of the investigations it thinks most useful to make, and a summary mth 

 notes of those -wkich have been executed. In this list, already long, we must 

 fitill include M. Schmidt at Athens, M. Poey at Havana, and lastly a gentleman 

 who has gained in France on this occasion a kind of celebrity, M. Coulvier Gravier. 

 It might have been predicted, from such a number of philosophers devoting 

 themselves to this study, that the history of meteorites would gradually be settled, 

 and 80 in fact it has turned out. We proceed to relate its principal features. 

 Meteors, when their size is considerable, present the same characteristics as 

 distinguished that of May 14th ; the same brilliancy, the same train of sparks 

 followed by a persistent cloudiness, often an explosion, and lastly, though less 

 frequently, a fall of aerolites. They are observed of all magnitudes, but, the 

 -smaller they are, the shorter is the extent of their path, the more rarely does an 

 explosion take place, and the train grows weaker. Finally, but witbont specific 

 lines of demarcation and by insensible degrees, we come to mere shooting stars. 

 The nature, origin, and laws of these latter should therefore be carefully studied, 

 and the conclusions drawn will apply to those which by way of exception are 

 large enough to constitute meteors. 



We may possibly be astonished to learn that these shooting stars, which on 

 the first aspect present an image of the most desperate irregularity, nevertheless» 

 on the whole, obey well demonstrated laws of periodicity. These laws have been 

 discovered by observations continued during a great number of consecutive 

 nights, and by taking at the end of each year the mean number of shooting stars 

 that have been observed in each successive hour from evening to morning ; this 

 is called the horary number, and, omitting certain exceptional nights of which we 

 will speak presently, it is found that this number increases progressively from 

 % P.M. to 3 A.M., then diminishes till day break, and probably throughout the day 

 till the next evening. In fact the number is 6 between 6 and 7 p.m., 10 between 

 midmight and 1 a.m., 1*7 between 2 and 3 a.h., and falls to nearly 13 between 6 

 and '7 am. In taking these observations, it was speedily noticed that all these 

 nights did not give identical results, and that those of the 10th, 11th, and 12fch 

 August are so rich in shooting stars as to count as many as 110 in an hour. This 

 superabundance at this epoch has been established since the commencement of 

 the century by a very great number of observers, and it is still more remarkable 

 that it appears to have existed from all antiquity. The proof of this is found in 

 the Chinese annals of which I have spoken, and which were examined by E. Biot. 

 These note particularly in the years 830, 833, and 835, a large maximum which 

 fell towards the end of July, reckoning this date by the Gregorian calendar. It 

 is known, however, that the axis of the earth does not retain an invariable 

 direction in space but describes, like the axis of a top, a cone the circuit of which 

 it completes in 23,868 years. It results from this that the time of the equinoxes 

 is continually changing, and that at the same dates from year to year the earth 

 occupies in its orbit progressively differing positions. Now, taking this circum- 

 stance into account, it is found that at the epoch when the Chinese observed the 

 maxima of the years 830, 833, and 835, the earth occupied in its orbit the position 

 it now has on Aug. 10th, where the maximum is now reproduced. The regularity 



