116 COSMOS. 



We can ascertain by measurement the enormous, wonder, 

 ful, 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- 



uius even ventured to deride the geognostic myth of the blocks and 

 stones. The Lygian field of stones was, however, very naturally and 

 well described iSy the ancients. The district is now known as La Crau. 

 (See Guerin, Mesures Baromitriques dans les Alpes, et Metiorologie 

 d^ Avignon, 1829, chap, xii., p. 115.) 



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

 (Tabor). Their general density maybe set down as 3, water being 1. 

 As to wliat has been said in the text of the actual diameters of fire-balls, 

 we must remark, that the numbers have been taken froin the few 

 measurl&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) about 1000, and for that 

 estimated by Sir Charles Blagden (18th January, 1783) 2600 feet iu 

 diameter. Brandes {UnterhaltHugen, bd. i., s. 42) ascribes a diameter 

 varying from 80 to 120 feet to shooting stars, and a luminous train ex- 

 tending from 12 to 16 miles. There are, however, ample optical caus- 

 es for supposing that the appai'ent diameter of fire-balls and shooting 

 stars has been very much overrated. The volume of the largest fiie- 

 ball yet observed can not be compared with that rf Ceres, estimating 

 this planet to have a diameter of only 7J English miles. (See the 

 generally so exact and admirable treatise, i )n the Connection of the 

 Physical Sciences, 1835, p. 411.) With the view of elucidating what 

 has been stated in the text regarding the large aerolite that fell into 

 the bed of the River Narni, but has not again been found, I will give 

 the passage made known by Pertz, trom the Chronicon Benedicti, Man- 

 achi Sancti Andrece in Monte Soracte, a MS. belonging to the tenth 

 century, and preserved in the Chigi Library at Rome. The barbaious 

 Latiji of that age has been left unchanged. '^^ Anno 921, temporihns 

 domini Johannis Decimi pape, in anno pontificatus illius 7 visa sunt sig- 

 na. Nam juxta urbem Romani lapides plurimi de cailo cadere visi sunt. 

 In civitate qua; vocatur Narnia tarn diri ac tetri, ut 7iihil aliitd credatur, 

 quarn de infernalibiis locis dedncti essent. Nam ila ex illis lapidibus 

 umis omnium maximns est, ut d-]cidens in fluuien Narnvs, ad mensuram 

 unius c'uhiti super aquas fiumim ', usque hodie videretur. Nam et ignitiB 

 faculce de coslo plurimoe omnibus in hac civitate Romani popuH vis<e S7int, 

 ita ut pene terra contingeret. Alice cadentes,^'' &c. (Pertz, Mmivm. 

 Germ. Hist. Scriptores, t. iii., p. 715.) On the aerolites of ^gos. I'ota- 

 mos, which fell, according to the Parian Chronicle, in the 78 1 Olym- 

 piad, see Bockh, Corp. Jnscr. Graec, t. ii., p. 302, 320, 340; also Aris- 

 tot., Meteor., i., 7 (Ideler's Comm., t. i., p. 404-407) ; Stob., Eel. Phys., 

 I., 25, p. 508 (Heeren); Pint., Lys., c. 12; Diog. Laert., ii., 10; and 

 see, also, subsequent notes in this work. According to a Moui^oliun 

 tradition, a black fragment of a rock, forty feet in height, fell iVoni 

 heaven on a plain near the source of the Great Yellow River in West- 

 ern China. (Abel Remusat, in Lametherie, Jour, de Phys., 1819, Mai 

 p. 264.) 



