* 



122 coSxMOS. 



whose accidental coincidence could alone convert a possible 

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



Gebler, NeuesPhysik. Worterhuche, bd. vi., abth. 3, s. 2129-2136.) 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 foixe 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 iEtna, 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, dn 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 planetaiy velocity of meteoric stones, he inclines to the hy- 

 pothesis of their lunar origin, always, how^ever, 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 tho 

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

 whose labors in recording the opinions and statements of preceding 

 writers are astonishing, repeats the theory,, and derides it the more 

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

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

 from the Sun: "Celebrant Gra)ci Anaxagoram Clazomenium Olym- 

 piadis septuagesimas octavae secundo anno prasdixisse caelestium littera- 

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

 iiiterdiu in Thracia) parte ad JEgoa flumen. Quod si quis prsedictum 

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

 agorae fuisse, 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 preserved 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. Moreover, 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 Suu 

 was regarded as "a molten fieiy mass" (fj.vdpoc ^idrrvpog). In accord- 

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

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

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

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

 Diatribe in Eurip. perd. Dram. Reliquias, 1767, p. 30. Diog. Laert., 

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

 reijardin" the origrin of fallin<? stars : a telluric origin from ascending 

 exlialations ; masses of stone raised by hurricane (see Av\?,ioi., Meteor ., 

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



