18. [Closing the Gates]
1. When those who come in from the country are within the city and evening is coming on, the signals should be given for dinner and for mounting guard. While the guards are getting ready, you should inspect the gates to see that they are shut fast; for disasters are very apt to result from the magistrates slackness in regard to bolts. 2. If a magistrate does not attend in person to the duty of bolting the gates, but delegate it to the sentinel, tricks can be played by the sentinel who wishes to let in the enemy by night. I will give examples.
3. One of them poured sand into the socket in the day-time, so that the bolt should remain outside instead of slipping down into the hole. Even bolts already in position are said to have been undone by pouring sand gradually into the socket, 4. and working the bolt to and fro noiselessly, so as to avoid notice, until, as the sand fell in, the bolt was gradually lifted and could easily be taken out. 5. Once, too, a gatekeeper who had been deputed by his general to fasten the bolt, stealthily cut a notch into it with a chisel or file, tied a knot of string round it, pushed home the bolt, and, after waiting a short time, pulled it up again by the string. 6. Another prepared a fine net with a string attached, pushed home the bolt enclosed in the net, and afterwards drew it up. The bolt has also been removed by being knocked upwards. Again, it has been taken out with a small pair of pincers: one nipper of the pincers must be hollowed like a channel, the other flat, so that you can receive the bolt with the channelled pincer and get a hold upon it with the other. 7. Another traitor succeeded in turning round the cross-bar without being noticed, when he was about to insert the bolt, so that it could not fall into its socket, and the gate could be opened afterwards with a push.
8. At a city in the district of Achaea, where they were plotting secretly to let in mercenaries, their first step was to take the measurements of the bolt in the following manner. 9. They inserted into the socket during the daytime a loop of fine strong string, with ends projecting but concealed; and when the bolt was inserted at night they pulled it up, along with the loop, by pulling the ends of the string, took its measurements and replaced it in the socket. Their next step was to get a key made to those measurements, which they did as follows. 10. They had a tube and a rush-mat needle forged: the tube was of the usual pattern, as was the greater part of the needle, including the sharp end; but its handle was made hollow, like the hole in a spike where the shaft is inserted. 11. A shaft was put in at the smithy, but taken out when they carried it home, so that the needle could be driven against the bolt and made to grip. The trick played to get the instruments made without the smith's suspecting the object for which he had made them was certainly a very clever one.
12. Once, too, the circumference of the bolt was measured, while it was in the socket, in the following way. Potter's clay wrapped in fine linen was inserted and pressed down with a tool round the bolt; then the clay was pulled up, an impression of the bolt taken, and a key made to fit it.
13. An agreement was once made to betray Teos, a Ionian city of considerable size, to Temenus the Rhodian, with the complicity of the sentinel at the gate. Among other arrangements they fixed upon a dark night when there would be no moon, on which the sentinel was to open the gates and Temenus was to enter with his mercenaries. 14. During the day before the night when the attempt was due, a man waited by the sentinel; when it grew late and the guards were being posted along the wall, and the gates were about to be shut, this man slipped out in the gathering darkness, after making fast one end of a ball of spun cord which would stand a good strain. 15. Unrolling the ball as he went, he made his way to a spot five stades from the city, where the attacking force had arranged to meet him. 16. When the general came round to shut the gates and as usual gave the sentinel the bolt to insert, he took it and, without making a noise or attracting notice, cut a notch in it with a file or a chisel, so that a thread would catch; next he slipped a loop round the bolt and let it down with the thread attached to it; and then, after shaking the bar to show the general that the gate was secure, kept quiet. 17. After a time he pulled up the bolt and tied the end of the cord to his person, so that, if by any chance he fell asleep, he would be roused by a pull of the cord. 18. Meanwhile Temenus was ready waiting, with the force which was to make the attack, at the place agreed upon with the man who had the ball of cord. It had been arranged that Temenus should go to the place and pull the cord: 19. and if the sentinel had succeeded in making all ready, he was to have fastened to the cord a piece of wool and let it go; on seeing this, Temenus was to have made a rush for the gates. But the sentinel was unsuccessful in his enterprise, he let the cord go with nothing attached to it, so that Temenus had plenty of time to escape unobserved: they had, after all, noticed during the night in the city that the cord was there, and so it was impossible to proceed further.
20. Another way in which a city was betrayed by a gatekeeper was this. He made a custom of going out with a pitcher just before the gates were shut, as if to fetch water; on reaching the spring he used to place stones on a spot agreed upon with the enemy, who would come up and discover from the stones placed there the message which the sentinel wished to convey. 21. If he was keeping the first watch, he put one stone down on the appointed place, if the second, two, if the third, three, if the fourth, four; he also signified to what point of the walls and to which guard-station the lot had assigned him. In this way he imparted the information which betrayed the city. In view of these various devices no precaution must be omitted: the magistrate must shut the gate in person, and not give the bolt to anyone else.
22. When engaged in any enterprise of the sort [i.e. an attempt to open a gate] yourself, you should take away the cross-bar altogether: for once some of the opposite party appeared unexpectedly and shut the gates again by main force, as the bar was still at hand; care must therefore be taken to prevent any such occurrences.