191. The line of resistance is occupied by the supports (outpost squadrons) placed in favorable locations, further strengthened by obstacles, intrenchments, etc., at a distance of about 2,000 yards from the reserve, or from the main body when there is no reserve.

192. The supports send forward about half their strength as pickets and cossack posts, which are placed about 1,200 yards from their supports and furnish the vedettes for the line of observation.

A squadron of cavalry as a support will, with its pickets, cossack posts, and vedettes, cover a front of about 2 miles.

193. The pickets are placed on or near the roads and, in addition to one or more double vedettes, furnish patrols according to their strength, which generally is not less than a platoon of 24 men.

194. Cossack posts consist of groups of 4 mounted men, 1 of them being designated as the leader. They take position under cover, dismounted, near the line of observation, and place 1 man, dismounted, as a vedette in the nearest position favorable for observation, seldom more than 50 yards off. The horses are held or securely tied.

Cossack posts are usually sent out from the support, but a picket may post a portion of its vedettes in the same way, and the reserve and main body may use special cossack posts. At night the number or strength of cossack posts and their vedettes may be doubled.

195. When the distance of double vedettes from their pickets does not exceed 100 yards the horses will, whenever practicable, be left with the picket. At greater distances, up to about 600 yards, a third man should be sent along to hold the horses of the other two; or Cossack posts may be established.

196. Cossack posts and pairs of vedettes are placed from 400 to 600 yards apart. The position of vedettes should be carefully selected, advantage being taken of high points to increase range of vision.

A single sentinel will be posted at the picket; supports will establish a single sentinel or one or more double sentinels.

Connecting vedettes are generally mounted, or at least have their horses at hand.

197. The commander of the support will designate examining posts when necessary. In accordance with the military situation and the orders he has received he will arrange for feeding, watering, cooking, and for shifting of saddles; he will also provide for the subsistence of his advance troops. His usual position is with the support, but for purposes of instruction and inspection he goes where his presence may seem necessary. Upon arrival of superiors he reports to them.

198. In close country observation must be supplemented by active patrolling. The principal reliance will be placed on the reconnoitering patrols sent to a distance to find the enemy. After gaining contact they must remain in touch, day and night. They must be strong enough to be able to send messengers whenever necessary; hence occasional reinforcement will be required.

199. Vedettes and sentinels are relieved every two hours, or oftener in severe weather. Cossack posts are relieved every twelve or six hours, according to the weather. Their horses should neither be unsaddled nor unbridled; everything must be in readiness for instant action.

Pickets and detached posts will not unsaddle or unbridle at night. During the daytime cinchas may be loosened and saddles shifted one-third at a time. Feeding and watering may also take place onethird at a time. Horses being fed should be removed a short distance from the others.

Pickets and cossack posts should prepare positions from which they can fire with effect and have the advantage of cover. It is to be accepted as a general principle that, in resisting an enemy, all parts of a cavalry outpost will place their chief reliance on the use of firearms; consequently arrangements must be made for such use to the best advantage.

200. In certain cases it may be of advantage for vedettes to remain mounted, but as a general rule, careful observation, especially with field glasses, can only be carried on dismounted.

201. The outpost cavalry is usually drawn from the divisional cavalry, or from the cavalry assigned to a separate command. The commander of the whole force will decide how much cavalry is to be included in the detail for outpost duty, bearing in mind the amount of cavalry available, its condition, the nature of the country, the state of the weather, etc.

202. The commander of the outposts will, in outpost orders, prescribe the distribution, both by day and by night, of the cavalry assigned to him.

It may be employed as follows:

1. By day it may form an advance screen several miles beyond the line of observation. At night the bulk of this force will usually be drawn in to the reserve, but patrols or small detachments would still be left in touch with the enemy, and at bridges, fords, and on the main roads in front of the position.

2. It may be used for purposes of reconnaissance and to keep up communication with bodies of independent cavalry in the neighborhood.

3. If it is considered advisable, in order to allow the horses to recuperate, or for other reasons, not to send cavalry far in advance of the line of observation, small detachments may be turned over to the commanders of the supports for patrolling, the remainder being held with the reserve.

4. When infantry has been severely taxed by marching or fighting, a large part of the outpost may temporarily be formed of cavalry. 5. When the number of mounted orderlies of infantry is for any reason insufficient, a few troopers may be assigned to the reserve and the supports for orderly duty.

6. Detached posts in distant or exposed positions may be occupied by cavalry during the daytime. When ample cavalry is available the infantry may, in open country and during clear weather, be relieved of a considerable part of its duty on the line of observation during the daytime by placing cavalry cossack posts at such points on or beyond the line as afford an extensive view of the country.

203. The general line to be occupied by the advance screen will be indicated by the commander of the outpost, but all the details should be left to the commander of the outpost cavalry.

ARTICLE V.

MARCHES.

GENERAL PRINCIPLES.

204. The principal work of troops in the field consists in marching. Battles come as occasional incidents in a campaign, but marches are of daily occurrence. Marching forms the basis of all operations, and success depends in a large measure upon its reliable execution. The mere fact of the punctual arrival at designated points of bodies of troops in good condition for battle may be of decisive importance. 205. Marches are executed in accordance with rules which vary with the military situation and distance from the enemy. They may be classified as follows:

(a) Ordinary marches, made on occasions when proximity of an enemy is out of the question, such as changes of station by marching in time of peace, marches to or from landings or railroad stations, marches of concentration at great distance from the front, etc.

(b) Marches in campaign, made in the theater of war, when coutact with the enemy is possible or probable.

(c) Marches into action, preparatory to or during deployment, with a view to an immediate attack or the occupation of a defensive position, the enemy having been located.

(d) Forced marches. Whenever unusual exertions are demanded of troops on the march in order to hasten their arrival, the result is a "forced march." In such cases the number and duration of the halts are diminished, the pace, especially of mounted troops, may be accelerated, the rests are reduced to the time necessary for cooking or feeding and the indispensable repose of the troops, and the movement continues, day and night, until destination is reached.

The term "forced marches" is also applied to a succession of marches of more than ordinary length.

(e) Night marches. Heavy fog, severe storms, or blizzards may limit the range of vision and bring about conditions similar to those which make night marches difficult.

(f) Practice marches, which are made with a view to exercising and instructing a command, or of accustoming it to field service.

With mounted troops and pack trains it is especially desirable that the backs of animals be hardened before entering an arduous campaign. Such marches afford an excellent opportunity for inspection of the field equipment, and contribute materially to the health and discipline of a command during periods of prolonged inactivity.

206. Unseasoned troops suffer severely on the march. The ranks of the infantry are depleted by the sick and foot-sore, the efficiency of the cavalry for mounted work is impaired and eventually destroyed by the prevalence of sore backs, and the horses and mules of field artillery and trains suffer with contused shoulders and go lame. Advantage must therefore be taken of every opportunity to accustom the troops to marching and thus to gradually bring the feet and muscles of the men and the backs or shoulders of animals into condition permitting severe and prolonged exertion.

207. The most important factors in maintaining and enhancing the marching efficiency of troops are strict discipline on the march and in camp, good food properly prepared and served at suitable hours, avoidance of excesses in eating and drinking, hygienic clothing, and care of the feet of the men and of the hoofs and backs of animals.

Intestinal disorders of young soldiers are due as much to the manner of eating and drinking as to the nature of the food consumed. In the Tropics special care of the person and moderation in the indulgence of appetite are essential to the preservation of fitness for work.

Subordinate officers will therefore have the men and animals of their units under constant observation, and make frequent inspections and inquiries with a view to immediate application of the remedies that may be suitable, at halts or in camp.

208. It is the duty of every commander on the march to be continually on the alert for opportunities-within the limits dictated by the military situation and regard for the discipline and health of the command-to ease the hardships of the troops. All unnecessary exertions waste the reserve strength of men and animals, and uselessly impair the fighting efficiency of the command.

ELEMENTS COMPOSING COLUMNS.

209. Columns on the march are composed of the troops, their light and regimental trains, the ammunition columns, the provision and forage columns, and of other parks, trains, and depots, depending upon the size of the force.