AEROLITES. 21 { J 



the sky illuminated by them with a feeble glow.* Many 

 shooting stars move merely as luminous points, and leave no 

 tail behind them. The combustion, attended with rapid or 

 slow disappearance of the tails, which are generally many 

 miles in length, is so much the more remarkable, as the burn- 

 ins: tails sometimes bend and sometimes move onward. The 

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

 disappeared, observed by Admiral Krusenstern and his com 

 panions during their voyage round the world, vividly calls to 

 mind the long shining of the cloud from which the great 

 aerolite of iEgos Potamos is said to have fallen, according to 

 the certainly not quite trustworthy relation of Damachos. 

 (Cosmos, vol. i., p. 133, and note f.) 



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 Tou- 

 louse (April 10th, 1812), and the observation of a fire-ball at 

 Tjtrecht, on the 23d of August of the same year, they were 

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

 in a star-like manner, and then to expand to a sphere of the 

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

 "YVrangeljf 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 pe- 

 riodicity 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. 



Meteoric stones fall the most rarely in a quite clear sky, 

 without the previous formation of a black meteor-cloud, with- 

 out any visible phenomenon of light, but with a terrible crack- 

 ling, as upon the 6th of September, 1843, near Klein- Wenden. 

 not far from Miihlhausen ; or they fall, and this more fre- 

 quently, shot out of a suddenly-formed dark cloud, accompa- 



* Forster's Mimoire stir les Etoiles Filantes, p. 31. 



t Cosmos, vol. i., p. 126, and note *. 



