We also know that the earth is round, because we can circumnavigate or sail around it.
Where can we see the shadow of the earth?
We can see the shadow on the moon, when the moon is eclipsed.
What is the shadow on the moon like?
It is round, like the shadow of a ball.
When the Earth comes between the sun and the moon, where does the shadow of the earth fall?
The shadow of the earth falls on the moon, as is represented in [Fig. 4].
Fig. 4.
What is this shadow on the moon called?