Page:Collier's New Encyclopedia v. 01.djvu/397

 &copy; Mt. Wilson Observatory

SOUTHERN PART OF THE MOON, AT LAST QUARTER. NIGHT ADVANCES FROM THE LEFT. THE BROKEN ROW OF YAWNING BLACK HOLES ALONG THE TERMINATOR BETWEEN DAY AND NIGHT INCLUDE, TOGETHER WITH THE SECOND ROW TO THE RIGHT, WHOSE BOTTOMS ARE STILL IN THE SUNLIGHT, THE GRANDEST "RING PLAINS" AND "CRATER MOUNTAINS" ON THE MOON. THE LARGE SMOOTH ONE AT THE BOTTOM IS "PTOLEMAEUS"