PORTION OF THE COSMOS. AEROLITES. 437 



indicate chemical diversity of substance. The form of 

 these igneous meteors is also extremely variable: some 

 appear only as phosphoric lines, and these so slender and 

 numerous, that Forster, in the winter of 1832, saw the sky 

 appear illuminated by them, as if covered by a faintly shining 

 veil ( 7 ). Many shooting stars move merely as shining 

 points, and leave no tail or train behind. The continued burn- 

 ing shewn in the more rapid or slower disappearance of the 

 trains, which are usually many miles in length, is the more 

 remarkable, because the burning train sometimes bends into 

 a curve, and makes but little progressive movement. The 

 circumstance observed by Admiral Krusenstern and his 

 companions during their voyage of circumnavigation, of the 

 luminosity continuing for some hours of the train of a fire- 

 ball which had itself long disappeared, recalls vividly to our 

 remembrance the " long shining" of the cloud from which, 

 according to the not indeed altogether trustworthy narration 

 of Damachos, the aerolite of ^Egos Potamoi is supposed to 

 have fallen (Kosmos, Bd. i. S. 395 and 407 ; English edit, 

 pp. xxi. and xxxii. Notes 60 and 87). 



There are shooting stars of very difterent magnitudes, 

 their apparent diameters sometimes increasing until they 

 are equal to that of Jupiter or Yenus. In the fall 

 of shooting stars at Toulouse, 10th April, 1812, and on 

 the occasion of a ball of fire observed at Utrecht on the 

 23d of August of the same year, a body of large dimensions 

 was seen to accrue, as it were, from a luminous point, first 

 shooting upwards with the appearance of a star, and then 

 expanding into a globe equal to the apparent magnitude of 

 the Moon. In very abundant falls of meteors, as in those 

 of 1799 and 1833, many fire-balls were undoubtedly inter- 



