It is somewhat circular in shape, and it covers a space of about 300 thousand square miles.

South of _Oceanus Procellarum_ and separated from _Mare Nubium_ by a goodly number of ring mountains, lies the little basin of _Mare Humorum_, the Sea of Humors, containing only about 66 thousand square miles, its central point having a latitude of 25 deg.

south and a longitude of 40 deg.

east.
On the shores of these great seas three "Gulfs" are easily found: _Sinus Aestuum_, the Gulf of the Tides, northeast of the centre; _Sinus Iridium_, the Gulf of the Rainbows, northeast of the _Mare Imbrium_; and _Sinus Roris_, the Dewy Gulf, a little further northeast.

All seem to be small plains enclosed between chains of lofty mountains.
The western hemisphere, dedicated to the ladies, according to Ardan, and therefore naturally more capricious, was remarkable for "seas" of smaller dimensions, but much more numerous.