Surveying and Measurement, Coastal Defense 10; ten units per square

Records of Military Preparation, Volume 218

Compiled by Mao Yuanyi original: "茅元儀" (Mao Yuanyi). Mao was a brilliant military strategist who compiled this 240-volume encyclopedia to address the crumbling defenses of the Ming Empire.

Records of Surveying and Measurement

Zhanduzai: This section title refers to the dual practices of "divination by observation" (zhan) and "terrestrial measurement" (du), which were essential for both navigation and tactical planning.

Surveying

Coastal Defense, Part 10

General Map of the Liaodong Coastal Region

Liaodong (the region "East of the Liao River") was the frontline of the conflict between the Ming Dynasty and the rising Later Jin (Manchu) forces.

Eight Detailed Maps of Liaodong

A Study of Strategic Military Geography in Liaodong

Bingxian: Literally "military dangers," this refers to the study of rugged terrain, mountain passes, and waterways that could be exploited for defense or could pose a risk to an advancing army.

Administrative and Military Affairs of Liaodong