February 1, 1918.

Problem 9

My dear Dick,—

This week my letter will be a short one, as it only contains one very simple problem.

You are on outpost duty and have been told that the General is very anxious to get one or two live prisoners. Your picquet is at some cross-roads a quarter of a mile south of the road AB marked on the map. You have reason to believe that it is probable that the enemy will patrol down the road AB. AB is a good road with strong fences on either side of it, and with ditches on the road side of the fence.

Does any special way of taking prisoners alive in this road suggest itself to you?

Solution.

A very good plan to adopt in these circumstances would be what the Japanese used to call the trap-door. If your post consists of six men, leave four under the leader at A and tell them to conceal themselves in the ditch, and place two, also concealed in the ditch, forty yards in front of the mat B. If the enemy’s patrol comes along, the men at B should allow it to pass them and then give a signal and at the same time themselves take steps to cut off the patrol’s retreat, whilst the four men at A prevent it advancing farther.

The above little scheme is so simple that I should feel that I ought to apologise for setting it, were it not that I am quite certain that three out of four of your comrades to whom you may set it will not give the proper solution.

I saw a similar little problem given to men of different regiments in India. The only troops who answered it properly were Pathans. It apparently much resembles traps which they set for one another in their inter-tribal fights. Although some twenty teams competed, neither British troops, Sikhs, Hindustani, Mohammedans, nor Rajputs ever managed to successfully catch their men.

Your affectionate father,
“X.Y.Z.”