NOTES. Iv 



bodies attached to it revolve around, the space nearest thereto is continually 

 heated by this movement, and thus there is produced a warmth which extends 

 down to the surface of the earth" (Meteorol. i. 3, p. 340). I have always 

 been struck by the circumstance that Aristotle avoids the term " crystal 

 heaven," although the expression affixed to stars, IvStStukva aGrpa, seems 

 to indicate the general idea of solid spheres, but without specifying the kind 

 of material. Cicero is not very intelligible on this point, but in his com- 

 mentator (Macrobius in Cic. Somnium Scipionis, i. c. 20, p. 99, ed. Bip.) 

 we find traces of freer ideas respecting the decrease of heat in increasing 

 height. According to him, the extreme zones of the heavens are subject to 

 perpetual cold. " Ita enim non solum terram sed ipsura quoque coelum, 

 quod vere mundus vocatur, temperari a sole certissimum est, ut extremitates 

 ejus, quse a via solis longissime recesserunt, omni careant beneficio caloris et 

 una frigoris perpetuitate torpescaut." These " extreraitates cceli," in which 

 the Bishop of Hippo (Augustinus, ed. Antv. 1700, i. p. 102, and iii. p. 99) 

 placed, as in a region of ice-cold water, the uppermost and therefore the cold- 

 est of all planets, Saturn, still belong to the atmosphere, for it is only still 

 higher above this extreme limit that, according to an earlier statement of 

 Macrobius (i. c. 19, p. 93), is placed the fiery aether, which, strangely enough, 

 does not prevent that eternal cold. " Stellse supra coelum locatse, in ipso 

 purissimo eethere sunt, in quo omne, quidquid est, lux naturalis et sua est 

 (the seat of self-luminous heavenly bodies), quse tota cum igne suo ita sphserse 

 solis incumbit, ut cceli zonge, quse procul a sole sunt, perpetuo frigore op- 

 pressse sirit." If I enter into so much detail respecting the connection of 

 ideas in meteorology and physics entertained by the Greeks and Romans, it is 

 only because, excepting in the works of Ukert, Henri Martin, and the ex- 

 cellent fragment of Meteorologia Veterum by Julius Ideler, these subjects 

 have hitherto been treated only in a very incomplete, and, most often, super- 

 ficial manner. 



( 201 ) .p. 106. That fire had the power of rigidifying (Aristot. Probl. xiv. 11), 

 and that the formation of ice itself is promoted by heat, were deeply-rooted 

 opinions in the Physics of the Ancients, resting on a fanciful antithetical 

 theory (Antiperistasis), or obscure ideas of polarity (a calling forth of opposite 

 qualities or states) ; Kosmos, Bd. iii. S. 15 and 29 (English edition, p. 15 

 and note 22). Hail, it is said, is formed in larger masses when the atmo- 

 spheric strata are warmer (Aristot. Meteor, i. 12). In winter fishing on the 

 shores of the Euxine, hot water was used to increase the formation of ice, in 



