to the Air, immediately in contact with the outermost crystalline sphere, formed of condensed and frozen air, which formed the wall encompassing the Kosmos. A remnant of Fire and Air still remained embodied in the Earth, but the great mass of both so distributed themselves, that the former occupied most part of one hemisphere, the latter most part of the other.[115] The rapid and uniform rotation of the Kosmos, caused by the exterior Fire, compressed the interior elements, squeezed the water out of the earth like perspiration from the living body, and thus formed the sea. The same rotation caused the earth to remain unmoved, by counterbalancing and resisting its downward pressure or gravity.[116] In the course of the rotation, the light hemisphere of Fire, and the comparatively dark hemisphere of Air, alternately came above the horizon: hence the interchange of day and night. Empedokles (like the Pythagoreans) supposed the sun to be not self-luminous, but to be a glassy or crystalline body which collected and reflected the light from the hemisphere of Fire. He regarded the fixed stars as fastened to the exterior crystalline sphere, and revolving along with it, but the planets as moving free and detached from any sphere.[117] He supposed the alternations of winter and summer to arise from a change in the proportions of Air and Fire in the atmospheric regions: winter was caused by an increase of the Air, both in volume and density, so as to drive back the exterior Fire to a greater distance from the Earth, and thus to produce a diminution of heat and light: summer was restored when the Fire, in its turn increasing, extruded a portion of the Air, approached nearer to the Earth, and imparted to the latter more heat and light.[118] Empedokles farther supposed (and his contemporaries, Anaxagoras and Diogenes, held the same opinion) that the Earth was round and flat at top and bottom, like a drum or tambourine: that its surface had been originally horizontal, in reference to the rotation of the Kosmos around it, but that it had afterwards tilted down to the south and upward towards the north, so as to lie aslant instead of horizontal. Hence he explained the fact that the north pole of the heavens now appeared obliquely elevated above the horizon.[119] [Footnote 112: Emp. Frag. v. 96, Karst., p. 98: [Greek: Ou(/tôs ê)=| me\n e(\n e)k pleo/nôn mema/thêke phu/esthai, ê)de\ pa/lin diaphunto\s e(no\s ple/on e)ktele/thousi, tê=| me\n gi/gnontai/ te kai\ ou)/ sphisin e)/mpedos ai)ô/n; ê(=| de\ ta/d' a)lla/ssonta diampere\s ou)dama\ lê/gei, tau/tê| d' ai)e\n e)/asin a)ki/nêta kata\ ku/klon.] Also:-- [Greek: kai\ ga\r kai\ paro\s ê(=n te kai\ e)/ssetai ou)de/ pot', oi)/ô, tou/tôn a)mphote/rôn] (Love and Discord) [Greek: keinô/setai a)/spetos ai)ô/n].