"'At about six in the morning, the farmer appeared, driving two greys, which he hooked to the plow, and carried on with his work. To us there appeared nothing suspicious in his actions. We watched him all morning. At noon he unhooked the horses and went home. We remained in hiding, afraid to leave, because we wanted to take no chances of being seen by the farmer. We had forgotten to bring rations with us, so it was a miserable wait until two o'clock, at which time the farmer reappeared, driving two blacks, which he hitched to the plow, and carried on until four o'clock, and then knocked off for the day. That night troops came through as usual, and were shelled. "'Next morning, at daybreak, we again took our stations in the hedge, this time bringing rations with us. The farmer used the same greys in the morning, but in the afternoon he appeared with a black and a grey, and again knocked off around four o'clock. No troops came through that night, and there was no shelling. "'Next day, the farmer repeated the previous day's actions,--two greys in the morning, and a black and a grey in the afternoon,--no troops, no shelling. "'We were pretty sure that we had him, but this arresting a spy on slim evidence is a ticklish matter. We didn't want to make a mess of the affair, or perhaps send an innocent man to his death, so the following day we again took up our stations. Sure enough, it was two greys in the morning, but in the afternoon he used two blacks. That night troops came through and were shelled. We had solved the problem. Two greys in the morning meant nothing. The actual signal to the enemy was the change of horses in the afternoon; two blacks meaning "troops coming through tonight, shell the road"; a grey and a black, "no troops expected, do not shell." "'When it got dark, and it was safe to leave the hedge, we immediately reported the whole affair to the Town Major (an English officer detailed in charge of a French village or town occupied by English troops), who, accompanied by us and a detail of six men with fixed bayonets, went to the farmer's house that night and arrested him. He protested his innocence, but we took him to Military Police Headquarters, where, after a gruelling questioning, he confessed.