118 CELESTIAL PHENOMENA. 



annals, which contain notices both of the appearance of 

 comets, and of great showers of falling stars, go back be- 

 yond the time of Tyrtaeus, or of the second Messenian war : 

 they describe two streams occurring in the month of March, 

 one of which was observed 687 years before the Christian 

 era. Edouard Biot has remarked, that in fifty-two 

 appearances of numerous shooting stars recorded in the 

 Chinese annals, the periods which recur most frequently 

 are from the 20th to the 22d July, old style. This stream 

 may therefore be the same as that which we now observe 

 about St. Lawrence's day (10th of August), supposing it to 

 have somewhat advanced( 77 ). If the shower of falling stars 

 of the 21st October, 1366, old style, of which Boguslawsld, 

 (the younger), has found a notice in Benessius de Horowic's 

 Chronicon Ecclesise Pragensis, be our present November 

 phsenomenon, seen on that occasion in bright daylight, we 

 should learn from the progression which has taken place in 

 the interval of 477 years, that the centre of gravity of this 

 system of shooting stars describes a retrograde path round 

 the sun. It also follows from the views which have been 

 here developed, that if years pass by in which neither of 

 the streams which have been hitherto indicated (that is, 

 those of November and August) are observed at any part of 

 the earth, the cause may be sought, either in interruptions 

 in the ring by vacant spaces or gaps between the groups of 

 asteroids, or, as Poisson thinks, in the influence which the 

 larger planets ( 78 ) may exercise on the form and position of 

 the ring. 



The solid masses which reach the earth, whether they 

 have been seen to fall at night from balls of fire, or in the day- 

 time from a small dark cloud usually in a clear sky, and with 



