On becoming a corporal some increase of responsibility is given our young soldier. He must wear as an indication of his rank two V-shaped stripes upon his arms and a narrow one down each trousers leg, of the color of the service insignia--red for artillery, yellow for cavalry, white for infantry. Instead of being conducted about in ranks, he now stands in line at the right end of his squad of eight men; when his squad is separate he is in command. He no longer walks post as sentry, but has charge of a relief, _i. e._, one of the divisions of a guard. The men of a relief all walk post at the same time. He must put his men on their posts as sentries, and stay awake and answer their calls so long as they are there. Many other duties, clerical, police, and provost, are given corporals, according to their ability. Vacancies constantly occur in the higher positions, and the custom is to fill them from the next lower rank. If our corporal has shown his ability to command firmly but in a manner pleasant to his associates while in his present grade, his chances are the best to be recommended for an appointment as a sergeant by the captain of his company. The corporal receives $15 and a sergeant $18 per month in the artillery, cavalry, and infantry. A sergeant's command is double that of a corporal, and on guard he divides his time in charge of the guard-house with another sergeant while overseeing the corporals and their reliefs. On drill he is over a section of two squads; in barracks he has charge of one sleeping-room; must keep order and enforce discipline. Thus still more ability to command other men must be shown. Corporals and sergeants are called "non-commissioned officers," because they receive a warrant from their colonel countersigned by the adjutant as authority of rank, in place of a commission from the President of the United States.