2d. Face the whole (except the right division) to the left, which moves forward on the word march from the chief. The divisions as they successively arrive on the ground from which the first division marched, will halt and front, follow the leading one and each other, till the whole are in column.
Received Rules.
3. If before any central point, or the left flank—The battalion makes a successive countermarch from the right flank towards the left, and when the right division arrives at the point from whence it is to advance, it again countermarches to its right, a space equal to its front, then faces and moves on, and is thus successively followed by part of the battalion. The other part of the battalion beyond the point of advancing, faces inwards, when necessary, makes a progressive march in file, then fronts, and follows by divisions as it comes to the turn of each, till the whole are in column.
A different Method.
Instead of passing according to the above method, much time may be gained, by the divisions on the right of the defile facing to the left, (commencing with the right division) march in file till opposite, and in full front of the division which is opposite the defile, or where the column is to advance from, then front, march forward, followed by the other divisions; the divisions on the left of the defile will face inwards, and when necessary, make a progressive march in file, followed as before, till the whole are in column.
Received Rule.
4. If behind the centre or the left flank.—The right part of the battalion countermarches from the right by files successively by the rear; and the other part of the battalion, as is necessary, makes a progressive march by files from its right to the central point, and there begins to countermarch at that point, the leading and each other division, fronts into column, and moves on.
A different Method.
To avoid loss of time in countermarching the divisions on the left as they successively arrive at the point they march from. Countermarch those divisions first on the ground they severally stand on, then face to the left; and when it comes to their turn march in file, front, and following in column, as they progressively and successively arrive opposite the point where the right division entered the defile.
It must be observed that in all countermarches of divisions on the ground they severally stand on, when passing to the rear, the division which stands opposite the point from which they are to march, must countermarch at the same time with the other divisions. See Am. Mil. Lib.