When there is sufficient time, wire entanglements should be constructed and shelter trenches dug outside the corral.

The diamond-shaped corral, as shown in diagram, is recommended for use in emergencies, for it can be rapidly formed and easily take the road again. The animals of the first two sections should be unhitched and placed inside. Openings may be left where deemed suitable.

When the nature of the ground permits, the teams of the first two sections may be required to countermarch before taking their places, thus obviating the necessity of unhitching.

571. The strength of the escort will depend upon the importance and size of the convoy, the risks it runs, the nature of the country, the length of the journey, etc. A convoy containing powder requires a stronger escort than any other, for it is necessary to prevent the enemy from firing into it.

572. As a rule, escorts of convoys should be composed of infantry, with enough cavalry for scouting and communication, and some engineers. The proportion of cavalry varies, being greater in open than in close country. Under average conditions a convoy of 100 wagons would require an escort of about 500 infantry and 50 cavalry. 573. The senior line officer of the troops commands the whole convoy; he may assign the second in rank to immediate command of the escort. He will consult with and, if practicable, defer to the wishes of the officer in charge of the transportation in all that relates to hours of starting, marches, parking of the trains, and guards to preserve order and prevent accidents. Officers casually with the convoy will exercise no authority therein.

574. After assigning detachments as police guard to the different sections, the commander will divide the remainder of the escort into advance cavalry, advance guard, main body, flank guards, and rear guard.

575. The advance cavalry. This body precedes the convoy by from 3 to 5 miles and scouts to the front and flanks. The necessary guides and interpreters should march with it. Important information will be sent to the commander of the convoy at once. Examination of bridges and defiles and of the country in the vicinity should be specially thorough; a temporary guard will remain at such points until the advance guard comes up.

576. The advance guard.-The advance guard, consisting principally of infantry, marches about 1 mile ahead of the convoy. Its duty is to search carefully the villages, woods, and defiles near the line of march; to remove obstacles and make repairs in the road; to drive off small parties of the enemy and delay larger ones, but not to engage in pursuit. Some cavalry is assigned to it for duty as messengers and in scouting.

The commander of the advance guard will report suitable places for halting or parking the convoy.

The leading section of the trains should never enter a defile until the advance guard is in possession of the farther end.

The advance guard should be continually in communication with

the main body of the escort by means of connecting groups.

577. The main body.-The greater part of the escort is kept together at the most important point, which may be near the head, in rear, or opposite the center, the latter being usually the most suitable position. Its duty is to cover the march of the convoy and to fight the enemy at the principal point of attack. It will generally be necessary to place a section of infantry at the head and another at the end of the convoy for its immediate protection.

578. Flank guards.-For protection against surprise small groups of cavalry will, if practicable, march at a distance of at least half a mile on both sides of the road. When the flanks are actually threatened, detachments from the main body will be sent in advance to covering positions on the right or left of the road, with orders to remain until the whole convoy has passed.

579. Rear guards.-The rear guard marches a short distance in rear of the wagon column, keeping a sharp lookout and being at all times ready to fight. Its strength should ordinarily be about of the escort and it should have the usual rear-guard formation. In addition to its other duties, it assists wagons that have fallen to the rear, and aids in transferring the loads of broken-down vehicles to reserve wagons. If the enemy attacks the convoy from the rear the rear guard endeavors to keep him at sufficient distance to prevent his firing on the convoy. It fights the enemy from defensive positions and if necessary, delays his progress by obstacles and demolitions. It should remain in touch with the main body of the escort by means of mounted messengers.

DEFENSE OF THE CONVOY.

580. If the various covering detachments perform their duties it will be impossible to surprise a convoy. The object of the commander will be to prevent the enemy from occupying, or to drive him from, positions permitting effective fire on the trains.

A check at the head stops the whole convoy, and the excitement caused by the enemy's fire may throw it into confusion. The flanks of a convoy are the parts most easily attacked.

581. As soon as the presence of an enemy is reported, all the teams will be ordered to close up; if the road is wide enough, the wagons will be formed in double column, and the march will be continued in the most orderly manner possible.

582. The commander should not seek a fight, but if the enemy holds a commanding position or a defile on the line of march, it will be necessary to dislodge him. The commander of the escort will

proceed to the attack with a large part of his force, but should not engage in a pursuit, which would involve the double risk of being caught in an ambuscade and of leaving the convoy without adequate protection. The convoy, halted during the combat, will resume its march as soon as the enemy has been driven off.

583. If the convoy be menaced by small hostile parties it will continue its march under the protection of the escort. Persons not in uniform attacking a convoy should be severely punished, in accordance with the laws of war.

584. The advance cavalry should report the presence of superior bodies of the enemy with the utmost dispatch, in order to give the commanding officer time to turn the convoy off on another road, to park it, or to start it in retreat if necessary.

585. Should the advance of superior forces of the enemy render it necessary to form corral, skirmishers will be sent out at once to delay the attack and gain time for the formation. Several well-mounted and reliable couriers will be dispatched to apprise the nearest troops of the situation. The commander selects good defensive positions at some distance from the convoy, intrenches if possible, and prepares for a stubborn resistance. Should the enemy be repulsed, his retreat will be carefully verified before breaking corral.

586. In case the fight takes an unfavorable turn and reinforcements can not arrive in time to change the situation, the commanding officer will try to escape with part of the train. If this be impracticable and the greater part of his force is disabled, he should try to cut his way out with the teams, after setting fire to the wagons.

ATTACK OF A CONVOY.

587. The most favorable time for attacking a convoy is when it is passing through a wood, a defile, or over a bridge; when it is going around a sharp bend in the road; when ascending or descending difficult slopes or passing over bad pieces of road; when the convoy is beginning to form corral; when the teams are being watered; or, whenever the conditions are such that the escort can not take rapid measures for defense. The assailant should endeavor to surprise the convoy while it is in a difficult situation.

588. The attacking force will endeavor to bring the convoy to a halt, throw it into confusion and make the principal attack from an unexpected quarter. The fire of artillery or machine guns will, if possible, be brought to bear on the convoy. In case of success the parts of the convoy that can not be carried off will be destroyed.

CONVOYS BY RAIL.

589. When the protection afforded by the troops of the line of communications is not deemed sufficient, the train to be convoyed will be preceded by a pioneer train consisting of some freight cars in front, and coaches with a working party and a portion of the escort in rear of the locomotive. The working party will be provided with the necessary tools and supplies for making repairs. The platform car in front of the locomotive may be protected by shields of boiler iron or by sand bags. The train to be guarded follows at a distance of 1 or 2 miles in rear, with the remainder of the escort distributed on the train.

CONVOYS OF PRISONERS.

590. In addition to an escort to oppose possible attempts at rescue, a guard of about 10 infantry soldiers and several mounted men is required for every group of 100 prisoners. The captives will be formed into companies and marched in column; their officers will march separately. Prisoners will be treated kindly, but must understand that attempt to escape will draw fire. If the convoy is attacked, the prisoners will be ordered to lie down. At night they will be placed in large, well-lighted buildings or inclosures.

CONVOYS BY WATER.

591. At sea, on the Great Lakes, and on large rivers, inlets, and estuaries convoy duty will be performed by the Navy. Water transportation on lines of communications in the interior derives its security principally from the presence of the forces in the field. For protection against guerrillas and raiding parties a steamboat of shallow draft and provided with machine guns and shelter against rifle fire should carry part of the escort and precede the transports. Means for disembarking the escort rapidly should be provided in order that hostile parties holding intrenched positions may be dislodged by a landing force. In the case of narrow streams or canals lined with woods or other good cover it may be necessary to have the escort march on both banks and clear the country as it advances.