s. When the army crosses large
streams, it will construct _tetes de pont_; and, if the bridges are
within walled cities, earth-works will be thrown up to increase the
means of defense and to secure the safety of the eventual base or the
strategic reserve which may occupy these posts.

Should the battle be lost, the army will retreat toward its base, in
order to be reinforced therefrom by detachments of troops, or, what is
equivalent, to strengthen itself by the occupation of fortified posts
and camps, thus compelling the enemy to halt or to divide his forces.

When winter approaches, the armies will either go into quarters, or the
field will be kept by the army which has obtained decisive success and
is desirous of profiting to the utmost by its superiority. These winter
campaigns are very trying to both armies, but in other respects do not
differ from ordinary campaigns, unless it be in demanding increased
activity and energy to attain prompt success.

Such is the ordinary course of a war, and as such we will consider it,
while discussing combinations which result from these operations.

Strategy embraces the following points, viz.:--

1. The selection of the theater of war, and the discussion of the
different combinations of which it admits.

2. The determination of the decisive points in these combinations, and
the most favorable direction for operations.

3. The selection and establishment of the fixed base and of the zone of
operations.

4. The selection of the objective point, whether offensive or defensive.

5. The strategic fronts, lines of defense, and fronts of operations.

6. The choice of lines of operations leading to the objective point or
strategic front.

7. For a given operation, the best strategic line, and the different
maneuvers necessary to embrace all possible cases.

8. The eventual bases of operations and the strategic reserves.

9. The marches of armies, considered as maneuvers.

10. The relation between the position of depots and the marches of the
army.

11. Fortresses regarded as strategical means, as a refuge for an army,
as an obstacle to its progress: the sieges to be made and to be covered.

12. Points for intrenched camps, _tetes de pont,_ &c.

13. The diversions to be made, and the large detachments necessary.

These points are principally of importance in the determination of the
first steps of a campaign; but there are other operations of a mixed
nature, such as p