SHOWERS OF SHOOTING STARS. 245 



and now for a third time approaches the spot so specially 

 pertaining to this shower, the great shoal must certainly 

 have passed, and only a few of the occasional Leonids will 

 this time enter the net. Many years must elapse before 

 we can again encounter the great host. They pursue 

 without interruption their appointed journey. For six- 

 teen or seventeen years they gradually retreat farther and 

 farther away from the neighbourhood of this world, then 

 they begin to turn round, and after the lapse of sixteen 

 or seventeen years more they regain our vicinity, when 

 great showers of Leonids are again to be anticipated. 

 Now we see how the great showers sometimes appear at 

 intervals of about thirty-three years. This is the period 

 which the swarm of little bodies require for the one 

 circuit. They did not appear in 1899. 



There are many other periodic showers of shooting stars 

 besides those notable Leonids on which we have dwelt so 

 long. None of the other showers, however, possess the same 

 importance as the Leonids, nor do they ever manifest celes- 

 tial splendour comparable with that of those of the 13th 

 of November. The Perseids, for example, which appear 

 from the 9th to the llth of August, are tolerably constant 

 in their appearance, but have little spectacular interest. 

 There is also another shower called the Andromedes, 

 which occurs on the 27th of November. It has produced 

 certain displays, one of the most remarkable of which took 

 place in 1872. The meteors were excessively numerous 

 on that occasion, but they were so short in their paths, 

 and so insignificant as to brilliance, that the spectacle^ 

 though of great scientific interest, could not be compared 

 as to splendour with that of the Leonids in 1866. 



