The DOUBLE STELLAR HEMISPHERE (hereinafter referred to as the Map) was printed in the 7th year of Chong Zhen Emperor of the Ming dynasty (1634), xylographically printed in eight vertical sections of fine Chinese native paper, well mounted with blue palace silk for screen hanging. Each section is 171,5 cm high and 56,5 cm wide, and when the eight sections are put together side by side, the whole Map is approximatley 200cm ×452cm, which includes the mounting margin. The Map is constituted of 20 colorful pictures ( 16 star charts and 4 pictures of astronomical instruments) and 2 legends.