eleven o'clock
A guard consists of a sergeant , a corporal , and ten men . They are on duty for two hours at a time , with intervals of four hours between each spell , in which intervals they sleep the sleep of tired men in the guard-tent , unless , as happened on the occasion previously described , some miscreant takes it upon himself to loose the ropes . The ground to be patrolled by the sentries is divided into three parts , each of which is entrusted to one man . Kennedy was one of the ten privates , and his first spell of sentry-go began at eleven o'clock . On this night there was no moon . It was as black as pitch . It is always unpleasant to be on sentry-go on such a night .