Books of Cosmography. Folio II.

This Diagram demonstrates that the earth is Spherical.

A diagram illustrating a lunar eclipse to prove the Earth's spherical shape. On the right, the Sun is depicted as a face with stylized rays. In the center, the Earth is shown as a circle divided into two halves: the right side labeled "Day" original: "Dies" and the left side labeled "Night" original: "Nox". Parallel lines of light from the Sun pass the Earth, casting a round shadow labeled "SHADOW OF THE EARTH" original: "UMBRA TERRAE" onto the Moon (also depicted as a face) on the far left.

If the earth were Four-sided original: "Tetragonica," referring to a square or rectangular shape. / its shadow would also appear in a four-sided shape during a lunar eclipse.

A diagram showing a hypothetical square or diamond-shaped Earth. Light from the Sun (on the right) passes the square Earth to cast a square shadow onto the Moon (on the left).

If the earth were Three-sided original: "Trigonica," or triangular.: its shadow would also have a triangular form.

A diagram showing a hypothetical triangular Earth. Light from the Sun (on the left) passes the triangular Earth to cast a triangular shadow onto the Moon (on the right).

If the earth were of a hexagonal shape: its shadow in a lunar eclipse original: "defectu lunari," literally a "failing of the moon." would also appear hexagonal, yet it is seen to be round.

A diagram showing a hypothetical hexagonal Earth. Light from the Sun (on the left) passes the hexagonal Earth to cast a hexagonal shadow onto the Moon (on the right).