586 COSMOS. 



slow disappearance of the tails, which are generally many miles 

 in length, is so much the more remarkable, as the burning tails 

 sometimes bend and sometimes move onwards. The shining 

 for some hours of the tail of a fire-ball which had long disap- 

 peared, observed by Admiral Krusenstern and his companions 

 during their voyage round the world, vividly calls to mind 

 the long shining of the cloud from which the great aerolite of 

 .ZEgos Potamos is said to have fallen, according to the certainly 

 not quite trustworthy relation of Damachos. (Cosmos, vol. i. 

 p. 122 and note.) 



There are shooting-stars of very different magnitude in- 

 creasing to the apparent diameter of Jupiter or Venus; 

 on the occasion also of the fall of shooting-stars seen at 

 Toulouse (April 10th, 1812), and the observation of a file- 

 ball at Utrecht, on the 23rd of August of the same year, they 

 were seen to form, as it were, from a luminous point, to shoot 

 out in a starlilce manner, and then to expand to a sphere of 

 the size of the Moon. In very abundant falls of meteois, 

 such as those of 1799 and 1833, there have been undoubtedly 

 many fire-balls, mixed with thousands of shooting-stars ; but 

 the identity of both kinds of fiery meteors has not been by 

 any means proved hitherto. Relation is not identity. There 

 still remains much to be investigated as to the physical rela- 

 tions of both; as to the influence pointed out by Admiral 

 "VVrangei, 23 of the shooting-stars upon the development of the 

 polar light on the shores of the Frozen Sea ; and as to the 

 number of luminous processes indistinctly described, but not 

 on that account to be hastily denied, which have preceded 

 the formation of fire-balls. The greater number of fire- 

 balls appear unaccompanied by shooting-stars, and show no 

 periodicity in their appearance. What we know of shooting- 

 stars, with regard to their divergence from definite points, is 

 at present only to be applied to fire-balls with caution. 



23 Cosmos, vol. i. p. 114 and note. 



