Chapter 37: On the poles of the heavens

1. The poles are little circles which run on the axis. Of these one is the northern which never sets and is called Boreas; the other is the southern which is never seen, and is called Austronotius.

Chapter 38. On the _cardines_ of the heavens.

1. The _cardines_ of the heavens are the ends of the axis, and are called _cardines_ (hinges) because the heavens turn on them, or because they turn like the heart (_cor_).