Mauretanians hunt hearing; a well steals camp talk

Theft of sound. The Mauretanians see sharpest of all. They recognize one approaching from far off, and they hear equally, though hearing is slower than seeing. Their sight is long by exercise and by nature: besides the runs they train, breathing very light air, they also abstain from everything hot and from salts, as being causes of dim sight.

So that they may never be caught sleeping, and an approach of enemies not escape them at night, they set under the neck that sleeping-wood of theirs, leaving the ear unhindered for hearing, dig a little pit, and hear both from far off — both voice and shouts. I have heard that the brigands of the western Gauls do the same. This is an improvised hunting of hearing.

If someone in a great camp should wish to learn the counsels of his own soldiers, or the secrets of the enemy — Art of knowing things to come — having dug a deep well, let him let down whom he wants, covering the mouth with some cloak. Nothing will escape the one sitting in it; he will recount to you what was said or what sounded, as if prophesying.

Let everyone trust my word: the one hunting long hearing by sitting with it, and the other, on a lightless night, to see something hidden on the earth, reasonably without fire. For the higher air is full of sound, and the plain earth strikes the sight with thickness and dulls the hearing with noise.