Treatise on Military Preparedness (Vol. 98)

...and the remaining fifty troops are divided into two shifts. Each shift consists of twenty-five men operating one patrol boat. In the first half of the month, the patrol inspector remains stationed while the elder leads the soldiers and boat out into the river to connect with other patrols. In the second half of the month, the elder remains stationed while the patrol inspector leads the soldiers and boat out into the river to connect with patrols. They alternate shifts, providing mutual support like the horns of a bull meaning: providing flanking support or forming a defensive pincer, all under the coordination of the dian-shi Records Clerk. The land routes within the county remain under the patrol and supervision of the dian-shi as before.

The Jiangdong Patrol Inspection Office has one patrol inspector, thirty archers, and one patrol boat. The jurisdiction extends fifteen li upstream to Xiangshuigou and ten li downstream to Caoxiejia. The river jurisdiction on the north bank, taking the center of the river as the boundary, is entirely under the management of the Jianghuai Patrol Inspection Office. The south bank is under the jurisdiction of this office, where the patrol inspector leads the archers.