Symzonia: Voyage of Discovery

When the sun has great southern declination, it is seen directly through the opening at the south pole, a little above the horizon--this gives an interval of bright light; and as the rays of heat are more refrangible than those of light [4], a sufficient degree of heat is experienced to ripen the most delicate fruits. At this season, during night, the rays of the sun are reflected from the opposite rim of the polar opening, and afford so much light as to render the stars invisible. The full moon is never seen at this period; for while the sun is in south declination, the moon fulls to the north of the equator, to give light to the north polar region, and the northern internal hemisphere. March and September are the darkest months. Both the sun and full moon are then in the equator, and shine very obliquely by refraction, into both polar openings. Yet, by reflection from side to side, they afford a faint light quite to the internal equator, where two reflected suns and moons are dimly seen at the same time. This circumstance had led the internals to suppose that there were actually duplicates of those luminaries. Their situation, it should be considered, did not admit of such observations of the celestial bodies, as were necessary to correct that error. During this season, the planets and stars of the southern hemisphere are visible, some directly, and others by reflection. This occasions great mistakes in their astronomical calculations, which they ascribe to the aberrations of the heavenly bodies. It never occurred to them that their field of vision was a limited internal concave sphere, and a great part of their firmament nothing but a reflection of the external heavens.