102 COSMOS. 



We can ascertain by measurement the enormous, wonderful, 

 and wholly planetary velocity of shooting stars, fire balls, and 

 meteoric stones, and we can gain a knowledge of what is the 

 general and uniform character of the phenomenon, but not 

 of the genetically cosmical process and the results of the 

 metamorphoses. If meteoric stones while revolving in space 

 are already consolidated into dense masses,* less dense, how- 



trale, t. i. p. 408,) how the Scythian saga of th sacred gold, which fell 

 burning from heaven, and remained in the possession of the Golden 

 Horde of the Paralatse, (Herod., iv. 5-7,) probably originated in the vague 

 lecollection of the fall of an aerolite. The ancients had also some strange 

 fictions (Dio Cassius, Ixxv. 1259,) of silver which had fallen from 

 heaven, and with which it had been attempted, under the -Emperor Se- 

 verus, to cover bronze coins ; metallic iron was, however, known to exist 

 in meteoric stones. (Plin. ii. 56.) The frequently-recurring expression 

 lapidibus pluit, must not always be understood to refer to falls of aerolites. 

 In Liv. xxv. 7, it probably refers to pumice (rapilli) ejected from 

 the volcano, Mount Albanus (Monte Cavo), which was not wholly 

 extinguished at the time. (See Heyne, Opuscula Acad., t. iii. p. 261; 

 and my Relation Hist, t. i. p. 394.) The contest of Hercules with the 

 Ligyans, on the road from the Caucasus to the Hesperides, belongs to a 

 different sphere of ideas being an attempt to explain mythically the 

 origin of the round quartz blocks in the Ligyan field of stones at the 

 mouth of the Rhone, which Aristotle supposes to have been ejected from 

 a fissure during an earthquake, and Posidonius, to have been caused 

 by the force of the waves of an inland piece of water In the fragments 

 that we still possess of the play of ^Eschylus, the Prometheus Delivered, 

 everything proceeds, however, in part of the narration, as in a fall of 

 aerolites, for Jupiter draws together a cloud and causes the " district 

 around to be covered by a shower of round stones." Posidonius even 

 ventured to deride the geognostic myth of the blocks and stones. The 

 Ligyan field of stones was, however, very naturally and well described 

 by the ancients. The district is now known as La Crau. (See Guerin, 

 Mesures Barometriques dans les Alpes, et Meteorologie d' Avignon, 

 1829, chap. xii. p. 115.) 



* The specific weight of aerolites varies from 1'9 (Alais) to 4'3 (Tabor) 

 Their general density may be set down as 3, water being 1. As to 

 what has been said in the text of the actual diameters of fire balls, we 

 must remark that the numbers have been taken from the few measure- 

 ments that can be relied upon as correct. These give for the fire ball of 

 Weston, Connecticut, (14th December, 1807,) only 500, for that observed 

 by Le Roi, (10th July, 1771,) atout 1000, and for that estimated by Sir 

 Charles Blagden, (18th January, 1783,) 2600 feet in diameter. Brandea 

 (Unterhaltungen, bd. i. s. 42) ascribes a diameter varying from SO to 

 120 feet to shooting stars, and aluminous train extending from 12 to 

 16 miles. There are, however, ample optical causes for supposing thai 

 the apparent diameter of fire balls and shooting stars has beou ver> 



