Long description

This figure has two parts. The upper part is a sketch of Mars shown as a circle. It is divided in two by a horizontal line through its middle, marking the equator. Some light grey shading indicates two areas across and south of the equator. This sketch is labelled: Aug. 6, 1672, 11h 00m past moon, CM = 213 degrees. The lower part is another sketch of Mars shown as a circle. Darker grey shading is shown across the equator and southern hemisphere, with a more distinct shape than in the top sketch. The sketch is labelled: Aug. 13, 1672, 10h 30m past moon, CM=290 degrees. Both circles also have a small mark at their top point, which signifies the south pole.