12*2 COSMOS. 



whose accidental coincidence could alone convert a possible 

 into an actual fact. The view of the orighial existence of 



Gehlei-, NeuesPhyslk. Worterbuche, bd. yi., abth. 3, s. 2129-2130.)^ If 

 we could assume volcanic forces to be still active on the Moon's surface, 

 the absence of atmospheric resistance would certainly give to their 

 projectile force an advantage over that of our terrestrial volcanoes ; but 

 even in respect to the measure of the latter force (the projectile force 

 of our own volcanoes), we have no observations on which any reliance 

 can be placed, and it has probably been exceedingly overrated. Dr. 

 Peters, who accurately observed and measured the phenomena present- 

 ed by Mtna, found that the greatest velocity of any of the stones pro- ' 

 jected from the crater was only 1250 feet to a second. Observations 

 on the Peak of TenerifFe, in 1798, gave 3000 feet. Although Laplace, 

 at the end of his work (Expos, du Syst. du Monde, ed. de 1824, p. 399).. 

 cautiously observes, regarding aerolites, " that in all probability they 

 come from the depths of space," yet we see from another passage 

 (chap, vi., p. 233) that, being probably unacquainted with the extra- 

 ordinary planetary velocity of meteoric stones, he inclines to the hy- 

 pothesis of their lunar origin, always, however, assuming that the stones 

 projected from the Moon " become satellites of our Earth, describing 

 around it more or less eccentric orbits, and thus not reaching its atmos- 

 phere until several or even many revolutions have been accomplished." 

 As an Italian at Tortona had the fancy that aerolites came from the 

 Moon, so some of the Greek philosophers thought they came from the 

 Sun. This was the opinion of Diogenes Laertius (ii., 9) regarding the 

 origin of the mass that fell at iEgos Potamos (see note, p. 116). Pliny, 

 whose labors in recording the opinions and statements of preceding 

 writei'S are astonishing, repeats the theoiy, and derides it the more 

 freely, because he, with earlier writers (Diog. Laert., 3 and 5, p. 99, 

 Hiibner), accuses Anaxagoras of having predicted the fall of aerolites 

 from the Sun: "Celebrant Grseci Anaxagoram Clazomenium Olyra- 

 piadis septuagesimae octavse secundo anno praedixisse caelestium littera- 

 rum scientia, quibus diebus saxum casurum esse e sole, idque factum 

 interdiu in Thracife parte ad iEgos flumen. Quod si quis prsedictum 

 credat, simul fateatur necesse est, majoris miraculi divinitatem Anax- 

 agorae faisse, solvique rerum naturae intellectum, et confundi omnia, si 

 aut ipse Sol lapis esse aut unquam lapidem in eo fuisse credatur; de- 

 cidere tamen crebro non erit dubium." The fall of a moderate-sized 

 stone, which is pi'eserved in the Gymnasium at Abydos, is also report- 

 ed to have been foretold by Anaxagoras. The fall of aerolites in bright 

 sunshine, and when the Moon's disk was invisible, probably led to the 

 idea of sun-stones. Moreovev, according to one of the physical dogmas 

 of Anaxagoras,. which brought on him the persecution of the theologians 

 (even as they have attacked the geologists of our own times), the Sun 

 was regarded as " a molten fiery mass" (fivdpoc dtdTvvpo^). In accord- 

 ance with these views of Anaxagoras, we find Euripides, in Phaeton, 

 terming the Sun "a golden mass;" that is to say, a tire-colored, bright- 

 ly-shining matter, but not leading to the inference that aerolites are 

 golden suu-stones. (See note to page 115.) Compare Valckenaer, 

 Diatribe in Eurip. perd. Dram. Reliqnias, 17G7, p. 30. Diog. Laert., 

 ii., 40. Hence, among the Greek philosophers, we find four hypotheses 

 regarding the origin of falling stars : a telluric origin from ascending 

 exhalations; masses of stone raised by hurricane (see Aristot., il/e/'cor., 

 lib. i., cap. iv., 2-13, and cap. vii., 9); a solar origin; and. lastly, an 



