The junior will salute at the command “Present Arms” given by the senior.  After the salute has been acknowledged, the senior brings both guards to the order.

364.  After the salutes have been acknowledged by the officers of the day, each guard is brought to an order by its commander; the commander of the new guard then directs the orderly or orderlies to fall out and report and causes bayonets to be fixed if so ordered by the commanding officer; bayonets will not then be unfixed during the tour except in route marches while the guard is actually marching or when specially directed by the commanding officer.

The commander of the new guard then falls out members of the guard for detached posts, placing them under charge of the proper noncommissioned officers, divides the guard into three reliefs, first, second, and third, from right to left, and directs a list of the guard to be made by reliefs.  When the guard consists of troops of different arms combined, the men are assigned to reliefs so as to insure a fair division of duty under rules prescribed by the commanding officer.

365.  The sentinels and detachments of the old guard are at once relieved by members of the new guard, the two guards standing at ease or at rest while these changes are being made.  The commander of the old transmits to the commander of the new guard all his orders, instructions, and information concerning the guard and its duties.  The commander of the new guard then takes possession of the guardhouse and verifies the articles in charge of the guard.

366.  If considerable time is required to bring in that portion of the old guard still on post, the commanding officer may direct that as soon as the orders and property are turned over to the new guard the portion of the old guard at the guardhouse may be marched off and dismissed.  In such a case the remaining detachment or detachments of the old guard will be inspected by the commander of the new guard when they reach the guardhouse.  He will direct the senior noncommissioned officer present to march these detachments off and dismiss them in the prescribed manner.

367.  In bad weather, at night, after long marches, or when the guard is very small, the field music may be dispensed with.

CHAPTER X.

MAP READING AND SKETCHING.

SECTION 1.  MILITARY MAP READING.

When you pick up a map, the first question is, Where is the north?  This can usually be told by an arrow (see fig. 1, section 1) which will be found in one of the corners of the map, and which points to the true north—­the north of the north star.

On some maps no arrow is to be found.  The chances are a hundred to one that the north is at the top of the map, as it is on almost all printed maps.  But you can only assure yourself of that fact by checking the map with the ground it represents.  For instance, if you ascertain that the city of Philadelphia is due east of the city of Columbus, then the Philadelphia-Columbus line on the map is a due east-and-west line, and establishes at once all the other map directions.