Art of War 9.23

高而銳 “high and sharp,” or rising to a peak, is of course somewhat exaggerated as applied to dust. The commentators explain the phenomenon by saying that horses and chariots, being heavier than men, raise more dust, and also follow one another in the same wheel-track, whereas foot-soldiers would be marching in ranks, many abreast. According to Chang Yü, “every army on the march must have scouts (探候之人) some way in advance, who on sighting dust raised by the enemy, will gallop back and report it to the commander-in-chief.” Cf. Gen. Baden-Powell: “As you move along, say, in a hostile country, your eyes should be looking afar for the enemy or any signs of him: figures, dust rising, birds getting up, glitter of arms, etc.”

There is some doubt about the reading 樵採. The T‘ung Tien and Yü Lan have 薪採, and Li Ch‘üan proposes 薪來.

Chang Yü says: “In apportioning the defences for a cantonment, light horse will be sent out to survey the position and ascertain the weak and strong points all along its circumference. Hence the small quantity of dust and its motion.”