Introductory Astronomical Writings of the Ancients

are inclined, for them it is truly divided by the horizon into more equal parts: until a certain region is reached, certainly southerly to us, in which the tropic is cut by the horizon into equal parts. But in our habitation, the summer [tropic] is so cleft by the horizon that, with the entire circle divided into eight parts, five appear above the earth [and] three lie hidden beneath the earth. Aratus seems to have directed his pen to this climate when he wrote his Phenomena. In which, when he discourses upon the summer tropic, he speaks thus:

Of this, divided into eight parts, five visit the heights
Of the lands, [and] three frequent the depths,
And the alternate returns of Phoebus are celebrated in the same way.

From this division it follows that the longest day is fifteen equinoctial hours, and the night, indeed, nine. In the horizon of Rhodes, however, the tropic is so delimited by the horizon that, while the entire circle is cut into forty-eight parts, thirty sections appear above the horizon, [and] eighteen lie hidden beneath the earth. From which division it happens that among the Rhodians the longest day has fourteen equinoctial hours, [and] the night nine, with halves of one hour added on either side. But the equinoctial circle is so divided by the horizon throughout the whole orb of the lands that a semicircle of it stands above the earth, [and] a semicircle is left beneath the earth. Whereby it happens that in this circle equinoxes occur. The winter tropi-