險, defined as 坑塹 (Ts‘ao Kung) or 坑坎 (Chang Yü).
and precipices,
阻, defined as 一高一下.
its marshes
沮, defined as 水草漸洳者.
and swamps.
澤, defined as 衆水所歸而不流者.
14. 不用鄉導者不能得地利
We shall be unable to turn natural advantages to account unless we make use of local guides.
[§§ 12–14] are repeated in chap. [XI. § 52].