Fig. 43. The Sun at the Equinox, seen from the poles and the equator.
Conv. III. v.
(Maria, Lucia, imaginary cities at the North and South poles).
We see, then, that these places have one day in the year which is six months long, and one night of equal length, and when it is day with one, it is night with the other.
Now on the circle on the globe where the Garamantes live [the equator], the sun when in Aries goes exactly overhead, not circling horizontally like a mill-stone, but vertically like a wheel, and exactly half of this wheel is visible above the horizon.
After this, the sun is seen to depart and go towards Maria for about 91 days; then in about the same time it returns, and enters Libra; then it goes towards Lucia for about 91 days, and in the same period returns. And this place, which circles the entire globe, always has equal day and night, on whichever side of it the sun is; and twice in the year it has a very hot summer, and twice a mild winter.
The regions which are between the two imaginary cities and the mid-circle, see the sun in different ways, according to their distance from these places, but the details, our author says, he will leave to the ingenious reader,
“Siccome omai, per quello che detto è, puote vedere chi ha nobile ingegno, al quale è bello un poco di fatica lasciare.”[387]
He draws attention to the interesting fact, which follows from the above, that in the course of a year (when the heaven of the sun has made a complete revolution and returned to the same place), every part of this globe on which we live has received an equal amount of daylight. And the essay ends in an apostrophe which recalls the reproof of Virgil to those who will not look up to the skies:[388]