for its protection than the rocky bed of a shallow mountain-stream. But now retreat, which must always be made piecemeal in a valley, until the outlet from the mountains is reached, is impossible for many parts of the line of troops; and that was the reason that the Austrians in Switzerland almost always lost a third, or a half of their troops taken prisoners.—
Now a few words on the usual way of dividing troops in such a method of defence.
Each of the subordinate positions is in relation with a position taken up by the principal body of troops, more or less in the centre of the whole line, on the principal road of approach. From this central position, other corps are detached right and left to occupy the most important points of approach, and thus the whole is disposed in a line, as it were, of three, four, five, six posts, &c. How far this fractioning and extension of the line shall be carried, must depend on the requirements of each individual case. An extent of a couple of marches, that is, six to eight miles is of moderate length, and we have seen it carried as far as twenty or thirty miles.