several operations, in a war, belong partly to Strategy and partly to Tactics — such as Passage of Rivers, Retreats and Descents.
It is therefore necessary to say a few words concerning them.
Passage of rivers.
In the passage of a river, we distinguish--
The point where we intend passing it.
The operation of the passage.
The first example of strategy, War in the United States
, is sufficient to show of what importance is the point of passage over a large river.
Different passages of the Potomac
, Mississippi, Ohio
, and Missouri
are discussed there; it is shown how different the result would be, if, instead of crossing, for instance, the Mississippi
, it was crossed at Cairo
If we have but one point where we can cross the river, and if our only line of retreat leads through this point, it must be fortified; the fort, called the tete-de-pont, should be large enough to hold at least a part of our army.
The more the bridge is of importance, the stronger the fortifications should be.
As regards tactical arrangements for the passage of a river in the presence of an enemy, we may say--
It is necessary to deceive the enemy concerning the real point of passage.
We should make demonstrations, feint attacks, and trials of passage on different points, with much noise, in order to attract the enemy's attention.
The greatest silence should be kept on the real point of passage, and the operations should be conducted with the utmost speed.
The construction of the bridge must, in many cases, be facilitated by sending troops in boats to the other side, to prevent the enemy's skirmishers molesting our men while at work.
3d. Strong batteries, of heavy caliber, should be placed in position, to hinder any artillery of the enemy being placed in like manner on the opposite side; the banks on our side should therefore slightly overlook those on the enemy's.
Large islands in rivers offer many advantages, as well as small streams flowing near the point of a passage in the main river, to place our boats and make our arrangements out of the enemy's sight.
It would be well to choose
a place where the river forms a curve, to be able to protect our troops by our artillery.
There should be good roads near the passage, to permit of an easy arrival of the men and materiel
To defend the passage of a river, the greatest care should
be taken to have all the different points well watched; at short distances smaller corps of observation should be disposed, in order to arrest for a short time the passage, or at least the forming of a bridge.
These corps place sentries along the river so as to form a continuous chain, and, in case of an attempt to cross, to give the alarm from one end of our line to the other..
A good ordnance or telegraph service should be organized, too.
The main force that defends the passage should form two or three corps, disposed so that they can easily join and render assistance to each other, and arrive in time at the endangered point.
There are two ways to act against an army passing a river.
The first is, to hinder the forming of a bridge and the passage of the enemy at the very ontset of his operation.
The second is, to allow a part of the enemy's army to pass without hinderance, and then attack it with a superior force, and try to defeat it.
Either of these two ways can be chosen according to circumstances, as shown in the following cases :--
In the campaign of 1799, the Archduke Charles
tried the passage of the Aar at Dettingen
He had disposed a formidable artillery on the right bank of the river, but, having no small boats, was unable to send one or two battalions to the opposite side, to keep the enemy's sharpshooters at a distance, before the bridge was commenced.
Opposed only by a few companies of riflemen hidden among the bushes and in the houses, they fired at and
killed most of the men engaged in the forming of the bridge, and hindered its completion till assistance arrived to render the passage impossible.
In the campaigns of the Prince Eugene, this general, opposed to General Vendome
, tried to pass the Adda in a very favorable spot, after having gained a march on the French
, however, being timely informed, arrived in all haste; the bridge was already commenced, and he could not prevent its being finished.
He ordered, therefore, some field-works to be raised in a large circle round the spot where the bridge was built; this was done simultaneously by his whole army, and finished at the same time as the bridge.
The Prince Eugene, thinking now the passage of his troops too dangerous to be undertaken, gave up his plan.
In 1809, Napoleon
crossed the Danube
from the Isle of Lobau
; when a part of his army only had passed, the Austrians loosened large ships laden with stones, and had them driven against the bridge, which was broken.
In the mean time, the Archduke Charles
had attacked the French
army with his own superior force, and, after a murderous fight which lasted all day, and in which the villages of Esslingen and Aspern were taken and retaken, the French
, after enormous losses, were obliged to retreat.
In this battle the Austrians lost about 20,000, and the French
25,000 men. The greatest loss they sustained at the end of the battle, when their troops, forming a convex line, were exposed to a concentric fire of artillery from the Austrians.
For acting in a similar way, it is necessary that the right
moment should not be lost, and not to permit too many troops to pass before the attack is made.
At Consarbruck, the French
general, Crequi, allowed the enemy to pass purposely, to attack him when the half of his army had gained the other side.
The passage commenced, but Crequi hesitated to attack.
When asked why he did not begin, he replied, that the more that passed, the more would be beaten.
At last he attacked; but the enemy had already assembled in such strength that he himself was totally routed.
Finally, there is one way more to render a passage ineffectual, which we may follow.
It is, to cross the river ourselves as soon as the enemy does.
In 1674, Montecuculi crossed the Rhine
to make war in France
, who was opposed to him, instead of defending the French
territory, crossed himself this river, and commenced operations in Germany
, and by this forced Montecuculi's return.
The following example will show in detail how the passage of a river might be conducted:--
Example: passage of the Limmat by Massena, 1799.
In 1799, the Archduke Charles
, with an Austrian army, was opposed by General Massena
; their two armies were separated by the Lake of Zurich
, the Limmat, and the Aar. The Archduke
was called back to Germany
; but he left
, with 27,000 men, in Zurich
and its environs.
Suwaroff, coming from Italy
, was to join Kutusoff
, being informed of the allies' plan, took the decision to pass to the offensive, to defeat Kutusoff
before he could make his intended junction with Suwaroff.
To effect this, he was obliged to cross the Limmat; and he therefore made the necessary arrangements to do so near Dietikon.
The division of Soult
had orders to pass the Lynth between the Lake of Zurich
and that of Wallenstadt; a part of the division of Menard
was to make a demonstration on the Limmat below Dietikon and near the junction with the River
near Dietikon forms a large curve; from Giessaker to Kl. Fahr the distance is 2000 yards.
A small river, the Schafflibach, runs into the Limmat almost in the middle of the curve.
Opposite the Schafflibach is a little wood, called the Glanzenberg; about 250 yards from which is a hill covered by another wood, called the Hardt-holz.
The space between the two woods is a meadow, and could be easily reached and swept by the batteries A and B.
The battery B overlooked completely the opposite bank of the river.
The bridge was to be established just below the Schafflibach and behind the wood Glanzenberg
, so that it was protected from the fire of artillery; this wood, then, would form a kind of tete-de-pont.
, at the point of passage, measures 100 yards wide; no isles or confluents were near this point, to serve as cover to the boats for the bridge as well as for the passage,
and they would therefore be obliged to be launched out of sight of the enemy.
The technical arrangements for the passage were left to Colonel Dedon
, of the Engineers
He had in his possession 16 regulation pontoons, with all the accessories; they were at Lunnern, forming a bridge there over the Reuss, and were to be transported by land to Dietikon.
Besides the pontoons, 37 boats, of different dimensions, could be had, the larger capable of containing 45, the smaller ones 20.
armed infantry soldiers; they were also to be transported a great distance by land.
The passage was to take place on the morning of the 25th of September, and the pontoons started only in the night of the 23d to the 24th from Lunnern to Dietikon.
The position of the Russians, on the right bank of the Limmat, was as follows:--
The right wing, General Durasoff
, 8 battalions and 10 squadrons, or 6000 men, placed near Wettingen and Wurenlos; 3 battalions and 400 Cossacks, or 2400 men, under General Markoff
, were placed near the spot chosen by Massena
; their position is shown in the plan.
Near Hongg 1000 cavalry were stationed.
The extreme left was formed by a reserve of 3000 men near Schwamendingen.
The headquarters of Kutusoff
were in Zurich
Two corps, composed of 5600 men, under General Gortschakoff
, were placed on the left side of the Limmat, between Wollishofen and Siehfeld.
3000 men were near Kloten
; the remaining 5000 men were opposed to Soult
on the upper part of the Lake of Zurich
Massena's passage of the Limmat 25 Sept 1799.|
had disposed many pickets along the Limmat, and had placed a sentry at nearly every 100 yards.
The position of the French
The division of Mortier
, 6000 men, opposed to General Gortschakoff
The 5th division, General Lorges
, 12,000 men, distributed from Schlieren to Baden
The 6th division, General Menard
, 8000 men, at Baden
and on the lower banks of the river.
The reserve, division of Klein
, in the Frickthal.
There dispositions for the passage were--
The division of Lorges
and part of the division of Menard
, in all 16,000 men, were to cross the Limmat at Dietikon — the Engineers
commanded by Colonel Dedon
, and the Artillery by Chef d'escadron Foy
As soon as the passage had been forced, General Lorges
was to leave a strong detachment opposed to the Russian
right wing under General Durasoff
, and with his main body to march by Fahr and Hongg toward Zurich
, to cut off the retreat of the Russian
left wing under General Gortschakoff
3d. General Menard
, with his remaining troops, was to demonstrate near Baden
, and to draw the attention of the 6000 Russians under General Durasoff
on him, while the real passage took place at Dietikon.
To prevent General Gortschakoff
attacking the rear of the passing divisions, General Mortier
was to attack him on the morning of the 25th.
5th. General Klein
was to station himself, with 4000 troops of the reserve division and cavalry, near Schlieren,
to be able to render assistance at any point where it should be required.
Without counting the 3000 Russians at Kloten
, four or five miles distant, Massena
, with 30,000 men, opposes 18,000; of these, 6000 are occupied on the right wing by a demonstration; 5600, under Gortschakoff
, are paralyzed by Mortier
's attack; so that, in fact, the main attack of Massena
is executed with 20,000 against 6400.
On the night of the 24th, General Lorges
, with his 16,000 men, noiselessly assembled near Dietikon.
had three and a half companies of Engineers, two and a half of which were ordered to bring the boats near the river and man them; the remaining company was to form the bridge.
One battalion and four companies of infantry were likewise put under the command of Colonel Dedon
, to assist in the transportation of the boats.
These boats had been placed in the rear of Dietikon, in a certain order, and all numbered; they were carried on the men's shoulders to the river, and disposed there in the same order.
Some of the boats, being very heavy, required 100 men to transport them; however, this part of the work was performed in the greatest silence, and without anything having been observed by the Russian
There were three kinds of boats — small, medium, and large.
The smallest were to enter the river above, and the largest below; the operation was to commence with the smallest boats.
The bank of the river was from seven to eight feet in height, so that the launching of the boats occasioned some difficulty; a detachment of sappers received orders to arrange planks on an inclined plan, so that the boats could be easily let down.
When all was ready, the boats were once more inspected, to see if everything was in order; the men then lay down near them, till the signal was given to begin the passage.
The artillery was arranged in the following manner:--
One battery, B, of 12-pounders, was placed, as shown in the plan, to sweep the country between the two woods; another battery, A, consisting principally of howitzers, was placed so as to be able to shell the barracks of the three Russian
battalions placed a little behind the Hardt-holz; finally, a battery of 12-pounders was placed opposite Oetweil, a little beyond, so as to sweep the main road from this place to Wurenlos, which is on the right side of the Limmat, and bordered by very steep hills several hundred feet high.
The object in having this battery was to prevent General Durasoff
coming to the assistance of Markoff
These dispositions were made in such silence that even the French
troops were unaware of them.
After midnight, the advanced guard, under General Gazan
, stationed itself at about 50 yards from the river.
The light boats were at the mouth of the Schaffibach, which at the time was dried up; these boats could hold about 180 men.
At the dawn of day, orders were given to lower the boats as quietly as possible into the river, for the troops of the
advanced guard to enter them, to pass to the other side and occupy the Glanzholz.
The nine light boats were more quickly lowered than the others; the infantry entered them, but being too heavily loaded, some difficulty arose in pushing them from the bank; therefore some of the men were ordered out. The noise this occasioned, though little, was sufficient to put the Russians on the alert.
One of the sentries fired; this was repeated by all the others along the river; and the alarm spread through the whole line from Baden
, and in a few minutes the entire Russian
army was under arms.
No time was to be lost; the boats were pushed into the river, manned, and rowed to the other side; and in three minutes from the time the Russian
sentry had fired the first shot, 600 French troops had landed in the Glanzenberg, all their batteries had opened fire, and the Russian
posts were driven back into the Hardt-holz.
The boats empty, they returned to the left bank, and transported more troops to the other side; and, before the bridge was completed, 8000 men had been carried to the right bank by the boats.
Scarcely, however, had they returned from their first expedition when the general
was beaten on the other side of the river, and as this could come from the 600 French who were ready to advance, as well as from the Russians, the fire on the left bank was ordered to cease, so as not to endanger their own troops by continuing it.
At a quarter to five o'clock the passage began, and half an hour afterward the French
were sufficiently strong to attack and drive the Russians from the Hardt-holz; at six o'clock this was accomplished.
The bridge was commenced at five o'clock, and at seven it was finished.
A party of sappers had been sent on the right bank to open a road for cavalry and artillery through the Glanzenberg.
At half-past 7, the remainder of Lorges
' 16,000 men, with their cavalry, crossed the bridge.
Two French battalions were directed at Oetweil to arrest the advance of General Durasoff
, if he should try to pass on the road to Zurich
The remainder, about 14,000 men, were arranged in order of battle near Fahr, and at ten o'clock began to advance in the direction of Hongg; after a short fight, General Markoff
was again repulsed, and in the course of the afternoon the French
advanced as far as Wipkingen and Schwamendingen.
In the morning, Mortier
had attacked General Gortschakoff
with the greatest impetuosity, and had succeeded in driving him toward Zurich
, thinking this was the main attack, called the 3000 reserves from Schwamendingen, and, with their help, Mortier
was in turn repulsed.
It was only in the afternoon, when Massena
had arrived at the gates of Zurich
, and even summoned Kutusoff
to surrender, that the latter felt all the danger of his position; he called in his reserve, and, with the assistance of some of the battalions arrived from the 5000 men opposed to Soult
, he was enabled to repulse Massena
, forcing him back as far as Wipkingen.
, in the mean time, with his reserve, advanced on the left side of the Limmat to support Mortier
, and they forced General Gortschakoff
to fall back on Zurich
's demonstration on the left wing had
been very successful.
To deceive the Russians as to his strength, he disposed his troops in single ranks, and made several attempts to cross the river, which he even accomplished in some parts.
In consequence of this, Durasoff
advanced still farther down the Limmat, leaving the decisive point behind him; when he discovered his mistake, he endeavored to reach Zurich
, and only arrived at a junction with Kutusoff
by making a great circuit.
The next day, Kutusoff
tried to open himself a passage in the direction of Winterthur; in this attempt he lost a great part of his army.
Passage of the Limmat by Massena 25th September 1799.|
Retreat and pursuit.
the moment we leave the battle-field to retreat, our operation becomes one of Strategy as well as of Tactics.
The direction in which we retreat is of the utmost importance.
In the example of the battle of Waterloo
this can easily he seen.
, after the battle of Ligny
, had retreated to Namur
, as many a general would have done, Wellington
's army would have been lost, and a double defeat the consequence; his retreat to Wavre
, and arrival at Belle Alliance, changed the defeat to the most decided victory.
The direction of our retreat will depend on many circumstances.
If we are co-operating with another army, we should retreat in this direction, to make a junction with it and obtain a central position between the enemy's armies.
We may also retreat directly into the heart of our country; or we may retreat parallel to the frontiers.
In the first example we have already spoken of this last.
The reasons for our retreat may be different, likewise.
We may retreat after a lost battle, as did Jordan
, for instance, in 1796, and Napoleon
in 1813, when driven back from the Bohemian
frontiers across the Rhine
; or before a very superior enemy, as the Russians did in 1812 before Napoleon
; or in consequence of a preconcerted strategical
plan, as in the campaign of the Archduke Charles
in 1796; or, in consequence of strategical movements of the enemy, to keep free our lines of communication — the retreat of Moreau
in 1796 was such.
We may also retreat to gain a favorable position for a battle, as did Napoleon
before the battle of Austerlitz
; and, finally, to approach nearer our depots and magazines, if we are in a devastated country — such was the reason of Napoleon
's retreat in the Russian
The arrangements for a retreating army belong more to logistics than to tactics; and to well understand them, it is necessary first to read the chapter on logistics.
I will only give the principal moments, and the rest will be found in the next chapter.
So long as a retreating army is not pursued, its march offers nothing particular; but from the moment the enemy is in pursuit, the question changes entirely; and it becomes most difficult after a lost battle.
Small armies, in which disorder can never be so very great, should try to evade pursuit by forced or night marches; but with large armies this is impossible — a slow and well-ordered retreat must be executed, with strong rear guards.
The service of the latter being very difficult, they are relieved every twenty-four hours; that is, the main body, arrived at a favorable place for defense, leaves a number of troops equal to the rear guard; these form in line of battle, and receive the rear guard, which now retreats, and joins the main body.
The new rear guard arrests as long as possible the progress of the enemy's advanced guard, and then begins its own retreat.
In large armies, the rear guard is generally composed
of a whole army corps.
In most cases, it amounts to one-third of the entire force.
As regards the disposition of the retreating columns, there are several: We may march our whole army on one road and in one mass, or on one road but in several columns, separated by one or several days' march; or we may retreat on several parallel roads, or on divergent or concentric lines.
Retreats on divergent lines are to be rejected; those on concentric ones, to be recommended.
As regards the three other modes, we can only say this — that, in the march for retreat as well as in that for advance, our army must be always so arranged that it can form from the marching order as quickly as possible in line of battle, or at least be able to bring, in a fight, at the same time as the enemy, a force equal to his own.
If the enemy pursues us having his army formed in one long column on one road, we might retreat in a similar way, or even in leaving a space of from one-half to one day's march between the columns, to prevent the incumbrance of the roads.
Retreats in one column have the great disadvantage of leading us very easily into difficulties by the incumbrance of the roads, which occasions the stopping of the whole army.
If the enemy pursues us disposed in several columns marching parallel, we would be obliged to do the same, as, by not doing so, our rear guard would risk being separated from the army by the flank columns of the enemy.
Finally, if pursued on our flank, our arrangements must be similar to a flank march, the disposition of which is given under Logistics.
The rear guard, according to its importance, should be several miles to half a day's march from the main army.
The commanding officer
should be most intrepid and enterprising, and at the same time cool and steady.
He should more often and more impetuously attack the advanced guard of the pursuing enemy than allow himself to be attacked; this sustains the morale
of the troops, and renders the enemy slower and less bold in his pursuit.
On the other hand, the pursuit should be conducted with the greatest energy and most unceasing activity, so as not to give the retreating army time to form again and reorganize.
Pursuits on the flank, if in our own country, are more advantageous than those in the rear, as they enable the pursuing army to prevent the retreat at the passage of a river or at any place it chooses to do so.
At the retreat of Napoleon
in the Russian
campaign, the Russian
army marched parallel with him on his flank; it arrived before him at Krasnoi
, and only by a miracle he saved part of his army.
The passage of the Beresina, in this same retreat, shows how dangerous it is, when the army is obliged to cross a river in the presence of, and opposed by, the pursuing enemy.
If we retreat in consequence of a strategical movement and are pursued by an inferior enemy, as was Moreau
in 1796, we should act like him — that is, to disengage our rear by trying to engage and defeat the pursuer.
, with only 30,000 men, was imprudent enough to accept the battle offered to him by Moreau
with 50,000 men. Latour
was defeated at Biberach
, on the 2d of October, 1796; after his victory, Moreau
continued his retreat unmolested.
Descents and expeditions.
here, again, we must consider the strategical and the tactical arrangement.
Descents are undertaken for the conquest of a country or an island; or they have only a restricted object, such as the destruction of arsenals, depots, ships, etc. etc.
of an enemy; or, finally, they are made to serve as a Diversion.
If the object of an expedition is the conquest of a country, the first thing necessary is to see that its means are sufficient.
If acting against an uncivilized nation, which has no regular army, or at least without such armed and disciplined men as our own, the result of such a descent is generally a favorable one.
The conquest of India
by the English
, of Egypt
by the French
, and the expedition by these powers united against China
, are examples of this.
For descents on islands, we have but to look at English history for examples.
, in his excellent naval history, gives a detailed description of all those made during the wars of the French
revolution and empire.
On the other hand, expeditions against a civilized country are attended with the greatest difficulties and danger.
The English armies in the United States
are a proof of this, and the Peninsular war might likewise serve as an example.
If we look at Moore
's retreat to Corunna
in 1809, and at Murray
's expedition to Tarragona
, we will see all the
dangers arising from such enterprises.
could never have succeeded in conquering the Peninsula
, had they not been assisted by the population of the whole country.
Expeditions with a restricted object, but still of a certain extent, are scarcely ever attended with the results we anticipate; or, at least, what we obtain by them is seldom an equivalent for the cost.
Examples of this are the English expedition to Antwerp
in 1809, and the great expedition to the Crimea in 1854.
To understand this, the reader must be well impressed with the principles of strategy.
An expedition is nothing else than a large detachment, or a division of our force separated from us by exterior lines.
If this detachment has a light task only to perform — such as the burning of undefended or slightly defended magazines, depots, and towns, or the destruction of some coast batteries, etc.--it is, in most cases, successful; that is, if the arrangements have been well planned, and the secret of the expedition well kept.
In these cases, the means are small, and no great preparation necessary.
If, on the contrary, the detachment has a certain role to play — such as acting against the enemy's rear, to force him to make detachments, to take possession of places, and, in one word, after its disembarkation, to execute an offensive operation in the country-its task becomes difficult.
These operations are then generally successful at the commencement, because the enemy is unable to have strong forces on every point of his coast; but, knowing once the point attacked, he can easily concentrate greater forces, and not only defeat, but utterly destroy these detachments as soon as they leave the protection of their ships.
In expeditions serving only as diversions, it would be much better to have but one detachment, which is quickly transported from one place to another, making descents near the larger towns, forcing them to pay contributions, and thereby obliging the enemy to a large display of force on his coasts.
Those troops are lost to him; he cannot make any use of them, in the continual expectation of being attacked.
On the other hand, we oppose to all his forces only that one, but continually changing detachment, which descends every-where, excepting on or near the point where the enemy awaits it. In such a way more is gained than by half a dozen expeditions, which would only conduct us to a division of our own forces, and draw them from the decisive point.
The tactical arrangements for a descent are very similar to those for the passage of a river.
We must distinguish the case of the descent being opposed or not. In the last case, speed is the principal requisition; the troops should disembark as quickly as possible, before the enemy can appear.
The vessels of war which accompany these expeditions should be disposed on the right and left sides of the descending troops, so as to sweep the country with their heavy guns.
Necks of land entering the sea are most favorable for the disembarkation, as they permit of a concentric fire from the ships, and the possibility of arranging the troops in good order before advancing, and their retreat in the same space covered by their ships.
It is exactly the same as a river forming a curve.
If the descent is to be made on a part where the enemy is in force, it is necessary to deceive him on the real point, to draw his forces in another direction, by making feigned
attacks, and by bringing the ships of transport in the night near the chosen point of descent, which should be made at daybreak.
All the large boats should be provided with boat howitzers, similar to those of Captain Dahlgren
, for instance, which are of an excellent pattern; they should be landed, and immediately serve as artillery to the troops going on shore, until their own field artillery is landed.
The disembarkation should be well flanked by the ships of war.
As soon as a sufficient number of troops is assembled, and if the enemy has been totally deceived as to the point of attack, they should advance, without losing time, against the rear or flank of the enemy, who is not prepared for such an attack.
If the landing is only slightly opposed, the troops should also advance as soon as possible to hinder the enemy assembling in too great force to prevent or endanger the disembarkation.
Islands near the main land are very favorable for descents, as the enemy has great difficulty to sustain his force placed there; and, once gained, they offer us a secure base for further operations.
As soon as the descent has been made, field-works should be raised to serve as a sort of tete-de-pont.
These works should be large enough to hold the greater parts of the troops from the expedition; the depots and magazines should also be established there; they should be situated so as to cover the ships, and enable the troops to re-embark at any moment and in any kind of weather.
The fortifications form the base of operation for the landed troops.
The position of Wellington
, and the fortifications of Torres Vedras to cover it, are a fine example.
The country in this part forms a triangle; on one side is the sea, on the other the Tagus
, and the third side formed the fortifications of Torres Vedras, so called from the village of this name.
was an excellent port for English vessels; and the peninsula which was formed by it and the sea was large enough to hold any army.
The most difficult and dangerous part, however, for a corps in an expedition, is its advance, or when ordered to operate in the interior of a country.
The Peninsular war is an excellent study for all such enterprises.
A few words on the defense may find their place here.
It is seldom possible to effectually oppose a descent; but
when accomplished, the disembarking corps should be crushed by superior armies.
The most certain way would be to oppose it but little; to leave a corps of observation at the point of descent, which retreats before the corps of the expedition.
But as soon as it is at a certain distance from its base, it should be attacked by very superior forces, and by means of tactical manoeuvres be entirely separated from its base.
In trying to cut off its line of retreat by strategical manoeuvres, the corps we intend to act against might be informed in time of our movements, and quickly retreat to its base; we would then gain nothing.
The result of a fight in which the corps is outflanked and turned by a superior force is, therefore, to be preferred.
The corps of observation left opposed to the expedition should throw up some field-works in opposition to those of the latter, so as to render its advance, at least, not entirely without danger.
It should also defend the passage of rivers, defiles, etc.