This passage shows that Dante was entirely orthodox and conservative in his geography, as far as longitude was concerned, and confirms us in the conclusion that he was so also with regard to latitude, and was not likely to accept contemporary evidence about lands south of the equator, or stars unknown to Ptolemy. In the _Divine Comedy_ there are several passages which refer to the same system, as for instance where Night is described as covering the whole region from “the Shore” to Morocco,[417] or where the time is stated to be noon on the Ganges, sunrise at Jerusalem, and midnight in Spain.[418] And in the _Quæstio de Aqua et Terra_ the system is thus clearly explained:— “As all these agree in believing [the naturalists, the astrologers, and the cosmographers], this habitable earth extends in longitude from Gades, which lies on the western boundaries of Hercules, as far as the mouths of the Ganges, as Orosius writes.[419] That longitude is such that at the equinox the sun is setting upon those who are at one of these boundaries, while it is rising upon those who are at the other, as astrologers have discovered by eclipses of the moon. Therefore the aforesaid boundaries must be 180 degrees distant in longitude, which is half the distance of the whole circumference.”[420] ------------------------------------------------------------------------ [417] _Purg._ iv. 137-139. [418] _Purg._ xxvii. 1-5. [419] Orosius says: “Europæ in Hispania occidentalis oceanus termino est, maxime ubi apud Gades insulas Herculis columnæ visuntur.... Asia ad mediam frontem orientis habet in oceano Eoo ostia fluminis Gangis.” [420] _Qu._ xix. 38-52. ------------------------------------------------------------------------ Gades is not the city of Cadiz, but two islands (the “Gades Insulæ” of Orosius), on which Hercules was said to have set up his Pillars, as a sign that no one should venture further; and they were thought to lie in the mouth of what we call the Straits of Gibraltar:[421]— ------------------------------------------------------------------------ [421] Moore, _Studies in Dante_ iii. p. 124. ------------------------------------------------------------------------ “quella foce stretta, Ov’ Ercule segnò li suoi riguardi, Acciochè l’uom più oltre non si metta.”[422] ------------------------------------------------------------------------ [422] “The strait pass, where Hercules ordained The boundaries not to be o’erstepped by man.” _Inf._ xxvi. 107-109. (_Carey_). ------------------------------------------------------------------------ Through these Ulysses sailed, never to return.[423] ------------------------------------------------------------------------ [423] _Inf._ xxvi. 106-142. ------------------------------------------------------------------------