Aeneas Tacticus 37: Dealing with mines.

37. The Discovery and Prevention of Mines

1. The digging of mines should be prevented by the following measures. If you think you are being undermined, the trench outside must be dug to a great depth, so that the enemy’s mine will open into the trench and their men will be seen plainly at work. 2. Where you have enough material, you should also build a wall in the trench, using the strongest and largest stones you can get. If you have no stones to build a wall, bring all pieces of wood you can find, 3. and if the mine runs up against the trench at any point, there pile up logs and the odd pieces of wood, and set light to them, covering up all other faces of the pile, so that the smoke passes into the enemy’s workings, and stifles the men at work there; it is even possible that many of them will die in suffocation. 4. Once the workmen in a mine were tormented by swarms of wasps and bees let loose into it.
5. If, however, you know at what spot they are digging, you should dig countermines and engage them underground, barring their progress and burning them out. 6. There is an old story in this connexion, Amasis, while besieging Barca, started to dig mines. The citizens, on realizing his intention, were greatly dismayed, fearing that he would defeat their vigilance, until a smith thought out a plan, which was to go round inside the walls with a bronze part of a shield and apply it to the ground. 7. There was no sound where the shield was applied, except at the point where the mines were being dug. There the mining caused it to ring. Here then the men of Barca dug countermines and killed many of the enemy’s miners. So this method is still employed at night in discovering the whereabouts of mines.
8. I have now described the best method of defence against the enemy’s stratagems. When you are starting mining operations yourself, the following will prove the most effective screen. 9. Take two carts, and tilt them up together from behind like opening doors, until their poles are high in the air and converge towards the same point; and tie the poles together. Next on this framework bind other poles and wickerwork, or anything else to serve as a screen above, and daub the whole with clay. The wheels will enable you to bring this contrivance wherever you want it, and to take it away afterwards, and under this shelter the miners can work.