63v

The Ocean

The great sea sits upon the round earth;
it covers and bathes the greater part of it,
and the land that stands above the waves
emerges from it like a mountain.
That which surrounds the land is called Ocean.^{1For medieval people this was the name of the single Ocean.}
Through the strait of the Spanish Sea,^{2The Strait of Gibraltar.}
Ocean pours [water] between the lands^{3Referring to the Mediterranean's placement in between the continents of Europe, Africa, and Asia.}
into a sea called the Mediterranean.

The Ebb and Flow of the Sea, that is, the Tide

Every like attracts like
and the moon rules over the humors.
Thus, when she extends over the great sea,
once per night and once per day
the water of the sea rises towards her
and leaves a great path uncovered
along the shores of the ocean. Then the moon passes
and the water that was low rises and returns.

The Horizon

Imagine you are on a high mountain
looking all around in every direction:
the sky will appear to you like the arch of a bridge,
set upon the earth like [the mouth of] an oven.
The circle around the edge is the horizon.
Now, note that where it is midday,
that hemisphere will be illuminated
and it will be night on the other side.