If at a halt, the indicated company stands fast; if marching, it is halted; each of the other companies is conducted toward it and is halted in proper order in close column. If the battalion is in line, companies form successively in rear of the indicated company; if in column of squads, companies in rear of the leading company form on the left of it. In close column formed from line on the first company, the left guides cover; formed on the fourth company, right guides cover. If formed on the leading company, the guide remains as before the formation. In close line, the guides are halted abreast of the guide of the leading company. The battalion in column closes on the leading company only. (_C.I.D.R., No. 19._) _To Extend the Mass._ 284. Being in close column or in close line: 1. _Extend on first (fourth) company_, 2. _MARCH_. Being in close line: If at a halt, the indicated company stands fast; if marching, it halts; each of the other companies is conducted away from the indicated company and is halted in its proper order in line of companies. Being in close column, the extension is made on the fourth company only. If marching, the leading company continues to march; companies in rear are halted and successively resume the march in time to follow at full distance. If at halt, the leading company marches; companies in rear successively march in time to follow at full distance. Close column is not extended in double time. 285. Being in close column: 1. _Right (left) front into line_, 2. _MARCH_. Executed as from column of companies. 286. Being in close column: 1. _Column of squads, first (fourth) company, squads right (left)_, 2. _MARCH_. The designated company marches in column of squads to the right. Each of the other companies executes the same movement in time to follow the preceding company in column. 287. Being in close line: 1. _Column of squads, first (fourth) company, forward_, 2. _MARCH_. The designated company moves forward. The other companies (halting if in march) successively take up the march and follow in column. _Route Step and At Ease._ 288. The battalion marches in _route step_ and _at ease_ as prescribed in the School of the Company. When marching in column of companies or platoons, the guides maintain the trace and distance. In route marches the major marches at the head of the column; when necessary, the file closers may be directed to march at the head and rear of their companies. _Assembly._ 289. The battalion being wholly or partially deployed, or the companies being separated: 1. _Assemble_, 2. _MARCH_. The major places himself opposite to or designates the element or point on which the battalion is to assemble. Companies are assembled and marched to the indicated point. As the companies arrive the major or adjutant indicates the formation to be taken. COMBAT PRINCIPLES. _Orders._ 290. The following references to orders are applicable to attack or defense.