METEORS. 139 



watched by Denison Olmsted (1791-1859), Pro- 

 fessor of Mathematics at Yale, and by the Ameri- 

 can physicist, A. C. Twining (1801-1884). These 

 investigators discovered that all the meteors 

 which fell during the great shower seemed to 

 come from the same part of the celestial vault. 

 In other words, their paths, when traced back, 

 were found to converge to a point near the star 

 y Leonis. This observation gave the death- 

 blow to the theory of their terrestrial origin. 

 The point known as the "radiant" was clearly 

 a point independent of the Earth. Olmsted also 

 recognised the fact that the shower had taken 

 place in the previous year, and he regarded it as 

 produced by a swarm of particles moving round 

 the Sun in a period of 182 days. Soon after this 

 it was noticed that the phenomenon took place 

 in 1834 and subsequent years with gradually 

 decreasing intensity. It was then remembered 

 that Humboldt had observed in November 1799 

 a very brilliant shower, and accordingly Olbers 

 suggested that another shower might be seen 

 in 1867. 



The falling stars of August were next proved 

 by Adolphe Quetelet (1791-1874) to form another 

 meteoric system ; and accordingly the theory of 

 Olmsted that the November meteors moved 

 round the Sun in 182 days had to be abandoned, 



