PROGRESS OF METEORIC ASTRONOMY 445 



the stillness of our autumn nights have such grand and far- 

 reaching influences, racing in almost interminable paths from 

 star to star, and disporting themselves amongst the planets, to 

 rush into their envelopes and cause a momentary blaze like 

 that so frequently pictured in terrestrial skies ! 



Old ideas regarding them were crude and altogether mis- 

 taken. Exact observations were lacking ; there were really no 

 reliable data from which a trustworthy theory of meteors could 

 be constructed. Shrocter, the German astronomer of more than 

 a century ago, often saw meteors during his vigils and calcu- 

 lated the height of one of them as more than one million 

 miles ! 



A good many curious theories were current about meteors 

 in former times. Halley thought them strata of inflammable 

 vapour raised from the earth, and then (taking fire at one end) 

 the running flame produced the apparent motion of the object. 

 Olbers concluded that they formed fragments of an exploded 

 planet. Hutton and Laplace believed they were thrown from 

 volcanoes in the moon. Clap, Day, and Carvalla considered 

 them to be terrestrial comets. Brewster and La Grange re- 

 garded meteors as bodies thrown off from the earth by volcanoes. 

 Dr. Blagden said they were electrical phenomena, while Sir 

 Isaac Newton supposed they proceeded from comets' tails. 

 Herrick correctly wrote, " Millions of small planetary bodies of 

 various magnitudes are revolving round the sun, and when any 

 of these dart into our atmosphere they become ignited, and are 

 seen in the form of shooting stars." 



It is not the intention to give a sketch of the history of 

 meteoric astronomy. The main facts are included in some of 

 our text-books and mere repetition would serve no useful end. 

 We must, however, mention certain features which appear to 

 have influenced the advance of our knowledge in a material 

 degree. In this connection the Leonid meteors of November 

 deserve prominent recognition. There is no doubt that this 

 recurring shower, more than any other, called the attention of 

 scientific men to a careful consideration not only of the pheno- 

 menon itself, but also of the whole subject of meteors. 



The display of 1799 was a fine one, but that of 1833 formed 

 a marvellous meteoric storm which excited world-wide dis- 

 cussion. Olmsted thought (and correctly so) that the meteors 

 formed a body similar to that of a comet. In later years 



