iii. Sufficient room in a straight line to haul down 600

or 1,000 yards. This should be measured out down wind and must be free from obstructions. It is possible to haul down in a smaller space, but this involves much preparation and a number of holdfasts are necessary.

RANGING.

=207.= _General instructions._

1. Ranging is the process of finding the elevation, fuze and line.

2. When the battery commander has given an order to load with any nature of projectile, that loading will be continued until an order to change is given.

3. With fixed ammunition, if a change of elevation or corrector be ordered when time shrapnel is being fired, Nos. 1 order “UNLOAD,” and guns are reloaded for the new elevation or corrector. A similar order should be given when for any other reason it is desired to empty guns already loaded, as, for instance, when ceasing fire.

If fixed ammunition is not used, and a change of elevation is ordered, guns loaded with the fuze for the old elevation will be fired at the new elevation. If for any reason it is required to empty guns already loaded, the order is “EMPTY GUNS,” and the guns are fired at once without any fixed interval.

4. As soon as ranging is completed the battery commander will send the angle of sight, elevation, corrector or fuze to the brigade commander, and in the case of howitzers the charge also.

=208.= _To find the elevation._

1. Under service conditions it is seldom possible to estimate with accuracy the distance the burst of a shell is short or over with regard to the target. The principle of ranging for elevation is, therefore, to find two elevations, the longer of which will throw the shell beyond and the other short of the target, thereby enclosing it in what is called a “_bracket_.”

This bracket is large at first, usually 300 yards.[20] If a smaller bracket is required one or more rounds, according to the nature of the ranging employed, are fired at the intermediate hundreds. This gives the 100 yard bracket, which in ordinary circumstances is the one required. The elevation is then verified by repeating the two ends of the bracket. =The important point is to make certain of this bracket.=

2. Ranging is either “_Collective_,” “_Single Gun_,” “_Section_,” or “_All Guns_.”

The method adopted should be that best calculated to obtain effective fire with the least delay, and with this end in view a combination of the different methods may sometimes be used. An example of combined “section” and “collective” ranging is given in Sec. =227=.

By “_Collective Ranging_”[21] is meant more than 2 guns fired in quick succession at the same elevation and fuze. The form that collective ranging should take in a 6-gun unit is the fire of half batteries alternately; in a 4-gun unit the fire of the three right guns.

[20] Or multiple of 300.

[21] Collective ranging does not apply to howitzers and heavy guns.

By “_Single Gun Ranging_,” “_Section Ranging_” and “_All Guns Ranging_” is meant ranging with one, two, or all guns fired singly.

In “_All Guns Ranging_” a single initial elevation is ordered, subsequent elevations being given out singly on the observation of the previous round.

In “_Section Ranging_” two elevations are ordered with or without an interval.

In “_Single Gun Ranging_” either of the above two methods may be followed, but only one gun is used.

3. The fall of the rounds is judged from the smoke of the burst of the shell or splash of the bullets, which should be clearly observed as short of or beyond the target.

4. In order to obtain good results when ranging with time shrapnel a length of corrector or fuze should be employed, which will give bursts on or just below the line of sight. When indirect laying is employed it may occasionally be advisable to commence with a corrector or fuze échelon series, in order to select a suitable length. (_See_ Sec. =209= (2).)

5. Elevation should always be given at first in round numbers, beginning, in the case of yards, at the nearest 100, or in degrees, at the nearest degree or half degree. It is seldom worth while to make a smaller change of elevation than 25 yards, or its equivalent.

When the whole series depends on the correct observation of a single round, that round should be repeated and another fired with 100 yards more (or less) elevation.

Further alterations in the elevation from the observation of the splash of the bullets and fall of the case of the shell, when visible, are made as required. This will often be necessary for individual guns.

If a shell is observed to strike the target, a verifying series of one or two rounds should be fired.

6. The battery commander details the method of ranging and the nature of the projectile thus:--

“COLLECTIVE” } { “CORRECTOR” or } { “RIGHT (CENTRE or } { or LEFT) RANGING” } ... { “PERCUSSION” or } { “NO. ... RANGING” } { or or } { “ALL GUNS RANGING” } { “LYDDITE.”

“_Collective Ranging._”

7. When collective ranging is employed the battery commander gives out one elevation and corrector for example:--

“Collective--Corrector 156--4600.”

This elevation is fired by the right half battery,[22] commencing from the right at battery fire 3 seconds unless otherwise ordered. The battery commander from the result of these rounds alters the corrector if necessary, and orders a fresh elevation to the left half battery to obtain his 300 yard or other bracket. He then sends down corrections for line for the right half battery unless one correction to the whole battery is advisable, in which case he will send it down before the new corrector and range. This process is continued until the size of the bracket is, if possible, reduced to 100 yards. (_See_ Sec. =227=, Example 1.)

[22] In a 4-gun battery by the three right guns.

“_Section Ranging._”

8. When a section is being used for ranging the battery commander gives out two elevations differing by 300 yards or multiple of 300 (the longer elevation first). The elevation which is given out first is fired by the right gun, the second by the left gun of the section, at an interval of 5 seconds, unless another interval is ordered. If the target is not bracketed two fresh elevations are ordered.

Should a gun of the ranging section become temporarily or permanently disabled, the section commander continues with the other gun of the section, or informs the section commander next him, who will place the nearest gun temporarily under his command.

“_Single gun Ranging._”

9. If one gun is used for ranging, elevations will be given out singly or in pairs, the general procedure for bracketing the target being similar to the above.

“_All guns Ranging._”

10. Ranging with all guns is in certain circumstances admissible, particularly when high explosive shell are alone to be used. Elevations will be given out singly. In the case of field guns this method would only be an advantage in very exceptional cases. It presupposes that the range from each gun is identical and that observation is easy.

=209.= _To find the fuze._

1. =As a rule no special ranging for fuze should be necessary.= The battery commander before or after ranging for elevation will select what he considers to be a suitable length of corrector and modify it later according to circumstances.

2. When fighting in a hilly country or when from any cause no reasonable estimate of the corrector can be formed it may prove economical in ammunition to fire an échelon before proceeding to fire with time shrapnel. (_See also_ Sec. =208= (=4=).) When an échelon is considered necessary it will, except in the case of howitzers and heavy guns, be fired before ranging for elevation commences. The échelon is fired by the three right guns from right to left at 5 seconds interval unless another interval is ordered. The fuze indicators, or fuze setters, are set at lengths increasing by 10, the order being “ÉCHELON] ... RANGE....” In ordering the initial corrector settings, the battery commander should endeavour to select an échelon which will give bursts in the air and on graze.

On this order the No. 1 of No. 1 gun orders his corrector to be set at the graduation ordered. The Nos. 1 of the other guns order their correctors to be set at a successive increase of 10. It may in very exceptional circumstances be necessary to fire a second échelon. The above procedure is then repeated.

3. If a gun misses its turn during the échelon the fact will be reported to the battery commander, and the gun will be fired when ready unless otherwise ordered. The section commander will, however, be careful that the gun is not fired during the échelon.

4. When fire is being corrected by observation from a distant observing station and the battery angle proves to be correct, any considerable discrepancy between the gun range and the plotter range will be due to a miscalculation of the angle of sight. The correct fuze will then be that for the plotter range.

=210.= _To find the line._

1. Except in the case of fleeting opportunities, battery fire will be continued till the battery commander is satisfied that the correct line of fire for each gun has been obtained. Even in the case of fleeting opportunities it will sometimes be advisable to fire a round of battery fire at small intervals to check the lines.

To avoid waste of ammunition, especially in the case of guns which cannot be unloaded, it may be advisable to increase the normal interval between the rounds of an échelon or at battery fire. Line corrections are preferably made on the fall of each round, but _see_ Sec. =208= (7).

2. The battery commander will correct the deflection for each gun unless he has delegated this duty to the section commanders. (_See_ Sec. =197= (3).) Should he consider from the first ranging rounds that his lines are not correct he should order an initial correction for the remaining guns.

3. To assist the battery commander in correcting for line when the observing station is not close to the battery, the number of each gun as it fires, also all prematures, should be reported by signalling or telephone. (_See also_ Sec. =197= (5).)

RANGING FOR HOWITZERS AND HEAVY GUNS.

=211.= _General instructions._

1. The general principles of ranging are the same as for field guns, but certain differences exist owing to the equipment, weight of shell, etc.

2. As a general rule, a steep angle of descent is a paramount condition for effective howitzer fire. When firing lyddite, an angle of descent of at least 20° is desirable.

3. Against troops in the open, the full charge should be employed in order to obtain the forward effect of a comparatively flat trajectory. When engaging objectives such as a wall, or buildings, which present a high vertical target, the full charge should also be used.

Redoubts or overhead cover on the contrary require a steep angle of descent; the same applies to trenches and shielded guns.

4. Howitzers frequently require individual corrections due to variations in the muzzle velocities of the guns, but such corrections should only be made on the observation of groups of rounds. The smallest correction which it is worth making is one equivalent to 25 yards.

5. When a change from lyddite to time shrapnel is made and it is known that lyddite shell range differently to the shrapnel a few rounds of time or percussion shrapnel should be fired to verify the elevation. Owing to the steep angle of descent it is often easier to observe the splash of the bullets of time shrapnel than the burst of percussion shrapnel.

=212.= _Howitzers._

1. Ranging can be carried out with lyddite, percussion or time shrapnel.

The ranging is carried out with one section or one gun of the battery, but all guns may be used for ranging if lyddite is to be used subsequently, and the target is of narrow front, or presents no obliquity to the battery.

2. When a section is employed for ranging, a bracket to approximate as nearly as possible to 300 yards, or multiple of 300 yards, should be ordered, but round numbers should usually be adhered to, such as 28°-25°, not 28°20´-25°20´.

This bracket is further reduced to one corresponding to about 100 yards, or 1-3rd of the original bracket. The elevation is then verified by repeating the two ends of this bracket.

When lyddite only is to be used, the bracket will be further reduced to 50 yards, and the two ends of the bracket repeated.

For howitzers fitted with the range drums graduated in yards for the fourth charge, the B.C. will range in yards as with other field guns, and will select the approximate ranges to start with, in accordance with the charge to be used, by means of the ranging rule provided.

If the range rule is not available, the following calculation will give the approximate range for different charges:--

When using full charge subtract ¼ from the _real_ range. ” fourth charge give the _real_ range. ” third charge add ⅓ to the _real_ range. ” second charge add ⅔ to the _real_ range. ” first charge double the _real_ range.

3. When ranging with one gun, or with all guns, only one elevation will be ordered at a time, the principles of bracketting as laid down above being adhered to.

4. _To find the fuze._--The battery commander, after ranging for elevation, may find it necessary to order an échelon (this will nearly always be necessary for batteries not provided with fuze indicators). The échelon is fired from right to left by the three right guns at 5 seconds interval, unless another interval is ordered, as in field gun batteries.

5. In the case of batteries not provided with fuze indicators, a fuze and an increment will be ordered, such increment to be a division or half division according to which most nearly corresponds with 100 yards.

If the battery commander begins ranging with time shrapnel the procedure will be the same as for other field guns except that collective ranging will not be used. (_See_ Sec. =208= (4)).

=213.= _Heavy batteries._

1. The procedure of these guns is identical with that of field howitzers, except that ranging will not be carried out with time shrapnel. At long ranges it is advisable to order one elevation at a time.

2. When firing with lyddite, as with howitzers, the 50 yard bracket should be verified. At distant ranges, however, the bracket should not be less than twice the 50 per cent. zone.

When time shrapnel is to be used the 300 yard bracket may be found with lyddite or percussion shrapnel.

3. The procedure in ranging for fuze is that of firing an échelon as laid down for howitzers.

DISTRIBUTION OF FIRE.

=214.= _General principles._

1. =Distribution of fire over the target allotted to the battery should, whenever possible, commence from the first round.=

This should not prevent a battery commander in the case of an indistinct target from ranging on the most conspicuous portion, and distributing his fire subsequently.

2. Assuming 50 yards to be the average distance required to burst a shell short of the target, and that the lateral space covered by the cone of dispersion of a shell is about 35 per cent. of the distance burst short, it will be seen that the width a battery at normal intervals can effectively cover when the lines of fire of its guns are parallel is approximately equal to its own front. By “_sweeping_” (_see_ Sec. =216=) it can cover a width of 3 times its own front.

3. When section commanders are ordered to correct for line (_See_ Sec. =197= (3)), each of them should be made responsible for a definite portion of the target. The extreme edge of a target should not be laid on, as a small error might cause the shell to be wasted.

4. If it is required to concentrate or distribute the fire of a battery over a front of a lesser or greater width than that covered when the lines of fire are parallel, it is effected by ordering concentration on, or distribution from, a named gun. When an aiming point is employed an angle is given to the battery, followed by the amount of concentration or distribution required.

5. The amount of concentration or distribution to be given will depend on the width of the target, the angular measurement of which varies with the range.

Thus:--

At 2,000 yds., 100 yds. measure 3°, 60 yds. measure 1° 45′. ” 3,000 ” ” ” 2° ” ” 1° 10′. ” 4,000 ” ” ” 1½° ” ” 50′. ” 5,000 ” ” ” 1° 10′ ” ” 40′. ” 6,000 ” ” ” 1° ” ” 35′.

These may be taken as the front covered by a 6-gun or 4-gun battery respectively when the lines of fire are parallel.

6. The angle given to the battery must bring the flank guns inside the flanks of the target. The total distribution required is the difference between the front covered by the battery and the extent of the target. This must be divided by the number of gun intervals to obtain the distribution between each gun. If the target is narrower than the front covered by the battery a similar rule applies, but concentration will be needed.

If a switch from one target to another is involved, the angle between the line of fire of a flank gun and the spot on which it is desired to direct the new line of fire of the same gun should be measured.

7. _Example I._--Supposing a 6-gun battery is required to fire at a range of 3,000 yards against a target measuring 3°, the fire of the battery with parallel lines will cover a front of 2°. An extra distribution of 1° is, therefore, needed. This amount divided by 5 will give 12 minutes for each gun interval, which would be taken as 10 minutes to prevent the fire of the further flank gun being outside the target. The order would then be “DISTRIBUTE 10 MINUTES, FROM NO. 1.”

No deflection is given to the named gun, but each of the remaining guns would be given 10 minutes left deflection for every gun interval between it and No. 1 gun.

_Example II._--Supposing it is desired to concentrate the fire of the above battery on the right to cover a front of about 30 minutes at a range of 3,600 yards, the battery commander’s order would be “CONCENTRATE 15 MINUTES ON NO. 1.” No deflection is given to the gun named; each of the remaining guns would be given 15 minutes deflection for every gun interval between it and the gun named, viz., No. 2 gun 15 minutes more right, No. 3 gun 30 minutes more right, and so on.

_Example III._--A 4-gun battery firing at a target whose angular extent is 4°. It is desired to switch the fire on to a target whose angular extent is 2°, therefore the difference 2° or 120 minutes divided by 3 (gun intervals) gives 40 minutes which is the concentration to be ordered.

When there is a considerable difference in range from one target to the other, parallelism should be first given to the guns before making the switch.

After the operation of ranging has been completed, the battery commander has to determine by what method of fire he will engage the objective. He may do so by one of the three methods described in Sec. =202= (1), combined, if desired, with “searching” or “sweeping.”

=215.= _Searching._

1. “_Searching_” means distributing fire in depth over an area of ground by successive alterations in elevation.

2. It will often be impossible to obtain the true range of a target, either owing to the difficulty of locating its exact position, or to want of time. All that can then be done is to ascertain two limits within which the target lies, and to search within those limits. Ranges at which fire is seen to be ineffective are cut out and the space under fire is thus gradually reduced.

3. Sometimes it will be necessary to range on a crest line behind which the target is located. In this case searching should not be attempted to a greater depth than 400 yards from the crest or other obstacle to view, unless the battery commander can obtain information as to the result of his fire or the approximate position of the target, as results are unlikely to be proportionate to the expenditure of ammunition. In this connection flank observing parties may be of great value.

4. Orders as to changes in elevation and number of rounds to be fired are given by the battery commander.

The amount by which the elevation should be increased for each series of rounds will depend on the depth of ground which is effectively covered by the burst of the shell. This amount varies from 100 yards at short ranges to 50 yards at extreme ranges.

Should the ground to be searched slope considerably to the front, the above increments should be increased; if to the rear, they should be diminished. When such is the case the angle of sight will be different for each successive range. It is generally inadvisable to alter this angle on the sights, but the slope can be allowed for by altering the corrector setting, decreasing it if the angle of sight is increased and _vice versâ_.

=216.= _Sweeping._

1. “_Sweeping_” means distributing fire in width over a front greater than a battery can cover in the ordinary way.

2. When sweeping fire is employed the lines of fire of the guns must first of all be opened out, the amount depending on the width of the target. To obtain the amount of sweep required after the guns have been opened out multiply the frontage subtended by the target in degrees by three for a 6-gun battery, five for a 4-gun battery, and ten for a section. This gives approximately the number of minutes sweep required. In giving the order to sweep, the battery commander will state in degrees or minutes the amount of sweep necessary, and such order will always be prefaced by the rate of fire required, thus:--Battery commander orders “RANGE ... SECTION (OR BATTERY) FIRE ... SECONDS, SWEEP ... DEGREES OR MINUTES.” On this order the first round from each gun is fired in the line ordered, and the second ... degrees (or minutes) to the right, and the third ... degrees (or minutes) to the left of the line of the first. This procedure is repeated for as long as is necessary, the fourth round being fired on the line of the first and so on.

The guns must be re-laid for elevation and direction after each round. If the battery is already at section or battery fire and sweeping fire is required, the battery commander must give the order:--“AT SECTION (OR BATTERY) FIRE ... SWEEP ... DEGREES (OR MINUTES),” as otherwise the procedure will be as in para. 3.

3. If it is desired to sweep an area with great rapidity, the battery commander will order:--“SWEEP ... DEGREES (OR MINUTES),” and the guns will be fired at gun fire. With guns fitted with traversing gear on the carriage the layer lays for direction for the first round only, the line for the second and third rounds being obtained by moving the traversing gear to the amount of sweep, right or left. The guns must be re-laid for elevation after each round. After the third round is fired the gun is traversed on to the original line and the direction checked by the sights. If it is necessary to repeat this procedure, the battery commander orders:--“REPEAT.”

4. _Searching and sweeping combined._--If the target possesses considerable width and depth a combination of searching and sweeping may be employed.

=217.= _Change of target._

1. When a change of target is ordered, the battery commander measures the angle between the new and old target. He determines whether any allowance is necessary to counteract the difference between the angle he has taken and that required for the battery. (_See_ Sec. =123= (4).) He then orders or communicates the angle to the battery thus: “ALL GUNS ... DEGREES MORE RIGHT (_or_ LEFT).”

2. With guns not fitted with No. 7 dial sight, if the angle is within the amount of deflection which can be given on the deflection scale, the position of the aiming posts may not have to be changed, and the order is given thus:--

“ALL GUNS ... DEGREES MORE RIGHT (OR LEFT).”

otherwise it is necessary to move the aiming posts and the order will be--

“LINES OF FIRE ... DEGREES MORE RIGHT (OR LEFT).”

METHODS OF ENGAGING VARIOUS OBJECTIVES.

=218.= _General instructions._

1. The choice of objective, the opening of fire, and the expenditure of ammunition are governed by the tactical situation and are dealt with in Chapter VII. The following sections deal primarily with the methods by which fire can be applied with effect to various objectives.

2. The methods of ranging are described in Sec. =208=, and the examples in Sec. =227= illustrate those methods. Officers are responsible for using their discretion as to which method should be employed so that the fire of their batteries may achieve the object in view.

=219.= _To register a zone._

1. A battery occupying “_a position in observation_” (_see_ Sec. =184=) may be called upon to “_register_” a certain zone or area of country. To do this the range should be obtained to various points in such a manner that fire may be opened rapidly on any objective that may subsequently appear in their neighbourhood.

Such points may be crest lines, hedges, bridges, roads, clumps of trees, buildings, the edges of woods, or the limits of open spaces over which the enemy may be expected to move.

Registering may be carried out with a section or single gun, time or percussion being used. It is advisable to number or letter the objects registered from the right, a careful record being kept of the points registered.

2. The degree of accuracy to which it is desirable to obtain the range to such points must vary according to the nature of the objective that may be expected to appear. The range to a crest on which artillery is expected to come into action must be accurately found. The limits of open spaces over which movement may be expected cannot, as a rule, be accurately defined. A few trial shots, therefore, may give sufficient indication for the purpose.

=220.= _Localities._

1. Villages or individual houses may be fired on by artillery in order to reduce their resisting power and render the approach to them easier. Field howitzers or heavy artillery firing lyddite should be used if available.

2. To destroy an individual house accurate ranging is necessary, only a sufficient number of guns or howitzers being employed for the purpose.

3. To destroy a village by setting it on fire or to prevent the massing of reserves in the streets a searching fire should be used.

4. To facilitate the attack on a village or house occupied for defence, field guns firing percussion shrapnel may be used, as well as howitzers and heavy artillery, as their projectiles are effective against personnel behind all ordinary walls. Accurate ranging is necessary; particularly for line, as it is necessary to hit each individual house.

5. If the edge of a wood is occupied by the enemy’s infantry, it should be ranged on in the same manner as a trench (_see_ below). A searching fire may be employed against troops taking cover in a wood, but as it will usually be difficult, if not impossible, to establish a bracket with any certainty, effect must depend to a great extent on chance.

=221.= _Staffs._

1. It may be possible to locate groups of officers forming staffs either mounted or dismounted. Such objectives should be ranged on rapidly and a quick rate of fire opened for effect till they either disperse or disappear.

=222.= _Cavalry._

1. Cavalry when mounted must usually be engaged on the move. It may present a variety of targets; a mass, a line more or less at right angles or parallel to the line of fire, or an area over which a number of comparatively small bodies is moving. The direction and pace of movement must always be reckoned with.

2. A mass will break up under artillery fire, so should be dealt with by rapid ranging, and an extremely rapid and intense fire till it breaks up, followed by a searching fire with suitable deflection to allow for movement.

3. To stop an advancing line the chief considerations are a suitable distribution and rapid changes of elevation, arranged so that the cavalry is always advancing into the fire.

At ranges under 2,000 yards it may be advisable to order lengths of fuze instead of corrector settings.

4. To enfilade a cavalry line moving across the front requires concentration of the lines of fire with varying elevations for each section and suitable deflection to compensate for movement.

5. Cavalry, covering a wide area, requires distribution both laterally and in depth, with deflection and alterations of range to compensate for movement.

6. Dismounted cavalry will usually be dealt with as infantry. Its led horses, if they can be located, form a vulnerable objective, which should be dealt with by rapid ranging followed by rapid fire for effect till the horses either disperse or gain cover.

=223.= _Artillery._

1. To engage a battery of which the flashes or dust thrown up by discharge are visible behind a crest, the crest should be bracketed, and searching fire employed for a suitable distance behind the crest. If the slope of the ground behind the crest is known, or can be ascertained, it may afford an indication of the distance behind the crest to which it is desirable to search.

2. A battery in action or attempting to come into action in the open engaged by a battery also in the open should be ranged on as quickly as possible and should be subjected to fire for effect at the earliest possible moment. The bracket should then be narrowed down and the fire maintained till the enemy’s fire slackens or becomes inaccurate. If the range is suitable and observation sufficiently easy, efforts may then be made to destroy the _matériel_ with percussion shrapnel. To do this each gun should engage a hostile gun, and the fire of each gun should be carefully corrected.

A concealed battery engaging a hostile battery in the open will adopt a similar procedure, but there is not the same need for haste, and the ranging may be more deliberate.

3. To neutralize a battery it should be subjected to a rapid, accurate and intense fire till its fire is mastered. It should then be observed and if it endeavours to intervene again it should be subjected to the same treatment. A hostile battery, the fire of which has been mastered, may be neutralized by a portion only of a battery, which should employ a rapid sweeping fire to compensate for the reduction in the number of guns.

If a rapid and intense fire is desired against hostile artillery it is preferable to employ a quick rate of section or battery fire.

4. Guns coming into action in the open can usually establish themselves in action before the process of ranging on them is completed, unless the range to some point in the immediate neighbourhood of the position has been previously ascertained. If this has been done the rapid opening of fire for effect may cripple the hostile battery before it is able to open fire.

5. Howitzers and heavy artillery, if available, are especially suitable for dealing with entrenched guns, the former using shrapnel against the personnel and lyddite against the entrenchments. The latter would preferably use lyddite against the entrenchments. Very accurate ranging is desirable.

6. Every effort should be made to locate the enemy’s observing stations. When located they should be engaged with a portion of the guns available.

7. The wagon lines of batteries in action form a vulnerable objective if they can be located. They should be dealt with in the same manner as the led horses of cavalry (_see_ Sec. =222= (6).)

=224.= _Infantry._

1. Artillery may fire on hostile infantry for any of the following reasons:--

i. To facilitate the advance of its own infantry. ii. To cause the hostile infantry to deploy.