A. THE POWER OF FIELD ARTILLERY.

1. THE FIELD GUN.

The field artillery of all the states that need be considered is armed with a rapid-fire gun provided with shields and capable under peace conditions of firing as many as twenty shots per minute. Its caliber varies from 7.5 to 8.38 cm. (Germany, 7.7; France, 7.5; Russia, 7.62, and England, 8.38 cm., the last-named being an 18 pdr.). The German gun fires shrapnel weighing 6.85 kg. (the Russian, 6.5, and the French 7.25 kg.) and high explosive shell of approximately the same weight, with an initial velocity of 465 m. (the Russian 588 and the French 530 m.). The projectiles are burst through the action of combination fuzes (in Germany graduated to 5000, in France and Russia to 5500 m.). The projectiles have a maximum range of 8000 m., when percussion fuze is used. Canister has been replaced by shrapnel, which bursts approximately 200 m. in front of the gun when the fuze is set at zero. The German field artillery is also equipped with a light field howitzer, cal. 10.5 cm., which fires shrapnel weighing 12.8 kg. (time fuze ranging from 300 to 5600 m.) and shell weighing 15.7 kg. (time fuze ranging from 500 to 5600 m.). The Germans use heavy field howitzers (cal. 14.91 cm., firing shell that has an extreme range of 6870 m.) in the heavy artillery of the field army. France uses the 15.5 cm. Rimailho howitzer, England a 12.7 cm. howitzer and another long piece of 12 cm. caliber.

Percussion shrapnel

is used for defense at short range, and in fire for adjustment; its effect depends upon the range and the nature of the ground. It is effective against troops lodged in tall timber. Masks, branches of trees, etc., frequently cause the premature burst of the projectiles.[108]

Percussion shrapnel is effective only when bursting immediately in front of the target (5-25 m. in front of it, depending upon the range). However, even in this case, the bullets often pass over low targets, such as skirmishers lying down, and low parapets afford sufficient protection. An adequate effect can be obtained only when the fire is directed on vertical targets. Soft ground, newly ploughed fields, terrain covered with snow or underbrush, small folds of the ground, or a rising slope, diminish the fire effect. When the angle of fall is 10 degrees or more (with the German piece at ranges of 3300 m. and over) half of the bullets penetrate the ground, the remainder ricochet and pass on at a greatly reduced velocity. The explosive or incendiary effect of shrapnel is insignificant owing to the smallness of the bursting charge. However, some incendiary effect is possible if the projectile strikes an easily inflammable target.[109]

Time shrapnel

(used in Germany up to 5000 m.) is fairly independent of the terrain, the burst being easily observed since the bullets are embedded in a “smoke-producing composition.” The extreme range at which this projectile can be employed is fixed by the facility of observing the fire and by the remaining velocity of the shrapnel bullets, both of which diminish as the range increases. Field guns, model ’96, may be effectively employed up to a range of 4000 m.; under 3000 m. their fire is so annihilating that decisive results are produced in a short time. (Par. 630 German F. S. R.). The use of the combination fuze, on account of its certainty of burst, either by time or percussion, permits the trajectory to be accurately determined in every case. This fuze also makes it possible to employ shrapnel against rapidly advancing targets, and in warding off a sudden attack at short range. The French Regulations give the width of the beaten zone of a single shrapnel as 20, that of two from the same piece as 25 m. The maximum depth of the beaten zone is 300 m. The angle of the cone of dispersion of the German shrapnel, model ’96, is 16 degrees at 2000 m. German shrapnel (model ’91) fired at a line of infantry did not strike lines following 250 m. in rear of the first, whereas in case of base charge shrapnel these lines would be safe only at 350-400 m. from the first line. The German shrapnel gives very good results when set to burst 30 to 150 m. in front of the target, the height of burst being regulated accordingly (approximately ¹⁄₃ of the whole number of hundreds of meters of the range). At ranges under 1500 m., an adequate fire effect may, however, be expected even when the fuze is set to burst the projectile 300 m. in front of the target. (Par. 30 German F. A. F. R.).

Shrapnel is most effective against skirmishers lying down from 1000 to 3000 m. when burst 28 to 22 m. short, and against standing skirmishers at the same ranges when burst 56 to 45 m. short. The two tables given below, borrowed from the work of Lieutenant-General Rohne on artillery tactics,[110] give an idea of the effect of a single time shrapnel, and of the effect per minute of shrapnel fire after adjusting upon the target:

More than 80% of the men struck by fragments and bullets from shrapnel bursting within 100 m. are disabled. The penetration of shrapnel bullets is so great, at ranges under 2000 m., that when they strike bones or vital organs of horses, they produce instant incapacity for action. This is especially true when the interval of burst is less than 100 m. The effect of shrapnel directed against batteries provided with shields is insignificant. Time shrapnel is the principal projectile employed by artillery against animate objects, provided these are not located immediately in rear of parapets, within tall timber, or under bomb-proofs. This projectile is ineffective against such cover on account of the flatness of the trajectory and the sensitiveness of the fuze.

Shrapnel is to be supplemented by shell filled with explosive charge, model ’88, which has a great explosive effect at extreme ranges and in tall timber. (See pars. 159-160 German F. A. F. R., in regard to action against shielded batteries).

Targets located immediately in rear of parapets or under light splinter proofs may be reached with time shell burst directly over or close in front of them. The depth of the beaten zone of this projectile is small, seldom exceeding 50 m., even when the fire is directed against targets in the open. About 75% of all the fragments are capable of inflicting disabling wounds when the interval of burst is short. The peculiar character of the projectile necessitates a very careful adjustment in range and in height of burst. The French obus allongé, a high explosive percussion shell (melinite charge; angle of the cone of dispersion exceeds 100 degrees) is employed only for the destruction of material objects.[111]

The French projectile, on account of the fuze used, bursts only after it has pierced thin walls or shields.

2. THE LIGHT FIELD HOWITZER.

The realization that the power of resistance of a defender lodged in deep trenches, could not be broken by the fire of guns having a flat trajectory, led to the re-adoption of a gun capable of high angle fire, which had been eliminated from the field artillery upon the advent of rifled cannon.[112]

For both flat trajectory and high angle fire, the light field howitzer, model ’98, employs shrapnel weighing 12.8 kg. (500 jacketed bullets, @ 10 g.; time fuze graduated from 300 to 5600 m.) and shell weighing 15.7 kg. (0.37 kg. explosive charge, model ’88; time fuze graduated from 500 to 5600 m.). As delay action fuzes are used, it is possible to utilize to the fullest extent the power of penetration of the projectile before it bursts.

A single shrapnel from a light field howitzer produces a greater number of hits, when the point of burst is favorably situated, than one fired from a field gun. However, the projectiles fired from the latter have a deeper beaten zone on account of the flatter trajectory of the piece, and a greater penetration owing to their greater remaining velocity. The German Artillery Firing Regulations (par. 30) consider the effect of both projectiles “very good” and of equal value at the principal ranges, when burst at a moderate distance (30 to 150 m.) from the target. The effect of shrapnel from the field gun and from the light field howitzer is considered adequate at ranges under 1500 m., when bursts are regulated to occur within 300 and 200 m., respectively, in front of the target. The superiority of the shrapnel fired from a field gun is due to the greater penetration of the jacketed bullets (a result of greater velocity of the projectile itself at the point of burst). But in this connection it is to be borne in mind that the effect of single shots only is here considered. The shrapnel fire of the field gun is considerably superior to that of the howitzer. This is due to the fact that the howitzer fires more slowly than the field gun and must expend twice the weight of ammunition to produce the same results. If, in addition, it is remembered that the field battery carries approximately 2¹⁄₂ times as many shrapnel as the light field howitzer battery, it is obvious that the fire of the former will be 2¹⁄₂ times as effective, against targets in the open, as that of the latter.

The superiority of the heavier projectile asserts itself when it becomes necessary to destroy material objects.

The shell fired from pieces having a flat trajectory is employed against troops immediately behind cover. The shell is burst immediately in front of, over, or in rear of the target, which is thus struck by splinters from above. The more nearly perpendicular the splinters strike the target, and the greater their number and weight, the greater will be the effect produced. The angle of the cone of dispersion is about 200 degrees; with appropriate points of burst, fragments weighing 15 g. (80%) incapacitate for action. In curved fire, at ranges beyond 2100 m., shell with delay action fuze is capable of penetrating the splinter proof cover usually employed in the field. At ranges under 2100 m. its angle of fall is too small to make an adequate effect certain.

3. THE HEAVY FIELD HOWITZER.

The heavy field howitzer employs shell weighing 39.5 kg., containing an explosive charge of 0.85 g., and fitted with a percussion fuze either with or without delay action. This shell is designed to penetrate the roofs of splinter proofs. An earth covering 5-6 m. thick is necessary to afford protection against these projectiles. At 3000 m. a 15 cm. shell produces a crater 1 m. deep and 2.4 to 3.6 m. in diameter, i.e., 2 cu. m. (in made ground this crater is three times this size). The heavy field howitzer is a very effective weapon against shielded batteries. A single shell, owing to its lateral explosive effect, is capable of placing a whole battery temporarily out of action.

4. EXPEDIENTS FOR MINIMIZING THE EFFECT OF FIRE.

Movements of infantry under artillery fire are unavoidable when firing lines are to be reinforced and when troops intended for the decisive attack are to be pushed closer to the enemy. Formations calculated to minimize the effect of the hostile fire must be taken up in time, since it is not always possible to make use of cover. The efficacy of the fire depends upon the accurate determination of the range and height of burst (fire for adjustment) and upon the careful observation of the subsequent fire (fire for effect).[113] The effect of this fire is considerably increased when the opponent’s infantry, against whom the fire is directed, takes up unsuitable formations (particularly broad line formations). Infantry has frequently found it advantageous to advance in small detachments moving rapidly at irregular intervals in extended order.

(a) Increasing the Difficulties in the Adjustment of the Hostile Fire.

A battery requires about 0.8 minutes (5 to 6 rounds with percussion fuze) to secure adjustment at ranges up to 750 m. The time required for securing adjustment at the longer ranges is as follows:

Narrow columns moving to their right or left front are very unfavorable targets for artillery, as it is very difficult for a battery commander to determine the relative position of bursts on the flank of a column with respect to the leading element thereof. Such shots are frequently considered as over. Numerous small columns, which make it difficult to designate a target, increase the time required by the hostile artillery to secure adjustment.

Troops should not be posted in the vicinity of conspicuous objects, as, for example, trees, visible at a great distance.[114] Intrenchments that have just been thrown up should be made to look as nearly as possible like the surrounding country by covering them with snow, sod, or brush. It is made more difficult for the hostile artillery to secure adjustment, if our infantry changes position to the front or to a flank, if it moves rapidly or advances by rushes.

It is easy, as a rule, for the artillery to adjust its fire upon masks, but difficult to determine the distance between mask and target. It is an advantage when masks are situated obliquely to a position. As masks (rows of trees) may cause the premature burst of projectiles having percussion fuzes, they should be at least 200 m. from the troops they are to screen.[115] When so situated they frequently afford better protection than actual intrenchments.

(b) Minimizing the Effect of Fire.

Formations that increase the effect of artillery fire, as for example lines and columns, and positions in which a flank is refused, should be avoided. It is a good plan to increase the number of targets and to employ narrow columns (column of twos) that are not too deep. Supports must be far enough in rear (300-400 m.) to prevent two targets being struck by one and the same shrapnel.

Of the close order formations used in the Russo-Japanese war, platoons or sections in columns of squads or twos,[116] separated by a maximum interval of 50 paces, were indeed found more suitable under fire than line formations, but the losses were nevertheless very serious except where cover screened the advancing troops from view or afforded them actual protection.

During the Franco-German war, line of platoons in columns of twos was found advantageous on several occasions.[117] This formation has the following disadvantages, however: it is very susceptible to flanking fire; the influence of the officers is principally restricted to the leading elements; intervals are easily lost and on that account it becomes more difficult to form line. It would seem to be better, therefore, to advance in line of platoons (or sections) in columns of squads, or, under flanking fire, in line of squads in columns of twos or files. In the last-named formation the intervals between squads are easily lost, however, and the company then becomes a dense skirmish line of from four to six ranks. To echelon the platoons slightly has very little value on account of the depth of the beaten zone of modern shrapnel.

In attacks made during the latter part of the Russo-Japanese war, both belligerents finally made use of thin successive skirmish lines for advancing; these lines followed each other at 200-300 m. and united again on reaching cover.

5. THE RESULTS OBTAINED BY ARTILLERY AGAINST VARIOUS TARGETS.

Germany. According to computations made by Lieutenant-General Rohne,[118] the following hits may be expected from every time shrapnel, model ’96, when burst an average of 50 m. short of the targets named:

The number of hits per minute obtained by a battery firing 50 shots at 500 m., 30 at 1000 m., 20 at 2000 m., 10 at 3000 m., and 4 at 4000 m., is as follows:

France.[121] According to the French Field Artillery Regulations (footnote to par. 277), a gun firing time shrapnel covers effectively a front of 25 m., and a battery of four pieces, a front of 100 m. This intensity of fire, which is obtained when each piece fires one shot with proper corrector and range settings (the battery four shots) Aubrat calls “Density 4.” When rafale fire (two shots per piece) is employed against a front of 100 m., with proper corrector setting, density 8 is obtained. When the front exceeds 100 m., the deflection of the pieces must be changed between successive shots (tir avec fauchage). To obtain density 8 against a front of 150 m., each piece must fire three shots, as prescribed in the regulations. When progressive fire (tir progressif) is employed, four different ranges are given, of which only one can be considered effective. When not sweeping, in this fire, each piece fires two shots, thus also obtaining a density of 8. A density of 1 always corresponds, therefore, to one round, fired, with proper corrector and range settings, against a front of 100 m. When a battery (four pieces) fires one salvo against a target having a front of 50 m., density 8 is obtained; by firing two salvos, density 16 is obtained.

The Commission d’études pratiques du tir has made a thorough investigation into the effect produced by shrapnel fire. The following table gives a general idea of the effect to be expected when firing against service targets (i.e., the percentage of figures one may expect to hit when employing fire of varying density):

A skirmish line 100 m. long, and lying down, would suffer a loss of 15% irrespective of its strength, from progressive fire (tir progressif; 32 rounds, density 8). If the interval between skirmishers in the open amounts to 1¹⁄₂ paces, for instance, the front would contain 62 skirmishers, and the resulting loss would amount to 9 men. If the men have placed their knapsacks in front of them, the loss would be reduced by half. A line of skirmishers of the same length and strength as the one considered above, would suffer a loss of 40%, or 25 men, when standing up or advancing. About 1¹⁄₂ minutes are required to fire one tir progressif, after adjustment has been secured. The same effect could be obtained in about 20 seconds by firing a rafale of eight rounds, provided the battery has accurately adjusted its fire.

6. THE EFFECT OF SHRAPNEL BULLETS ON ANIMATE TARGETS.[122]

The wounds produced by shrapnel bullets are similar to those caused by the lead bullets of the infantry weapons of the past. When the bullet strikes normally to the surface, it produces a wound circular at the point of impact and considerably enlarged at the point of exit; bones are frequently shattered; and the most serious effect is the introduction of foreign substances, such as pieces of cloth, particles of earth or sand, or of the material in which the bullet is embedded.

The effect of shrapnel bullets on animate targets depends upon the striking energy of the bullets (expressed by kgm.) and on their density, those of smaller cross-section having the greater penetration. The closer the point of burst is to the target, the greater the velocity, and, naturally, the effect.

Opinions differ as to the amount of “striking energy” necessary to put animate targets out of action. In France, an energy of at least 4.8 kgm. is considered necessary to disable human beings, and for horses an average of 19 kgm., while in Germany, an average energy of 8 kgm. is deemed sufficient. The 10 g. hardened lead bullet, having a diameter of 12.3 mm., retains this energy until its remaining velocity is only 120 m. At ranges up to 1500 m., over 80% of the men struck by fragments and bullets from shrapnel, bursting within 300 m. (and beyond this range from shrapnel bursting within 150 m.) are put out of action. (Par. 30 German F. A. F. R.). In comparison, artillery projectiles produce a greater number of fatal wounds than infantry projectiles.

It is worthy of note that the packed knapsack affords protection against all shrapnel bullets having a velocity of 100 m. and against half of those having a velocity of 200 m. The overcoat roll stops shrapnel bullets having a velocity of less than 250 m. The penetration of these bullets is so great, at ranges under 2000 m., that when they strike bones or vital organs of horses, they produce instant incapacity for action. This is especially true when the interval of burst is less than 100 m.

B. INFANTRY FIRE.[123]

The modern infantry rifle, cal. 6.5 to 8. mm., is a magazine arm employing steel jacketed, pointed bullets, arranged in clips. The adoption of automatic rifles is contemplated. In these rifles the recoil energy is utilized for throwing out empty shells and for placing a fresh cartridge into the chamber at the same time. The objections made to the adoption of such a rifle (complexity of the mechanism, danger of wasting ammunition) are similar to the reasons advanced against the adoption of breech-loading and magazine rifles. In addition to the increased rate of fire, the advantage of eliminating the effect of the recoil on the skirmisher must not be underestimated. Moreover, the elimination of the recoil makes a further increase in the initial velocity of the projectile possible.

The effect of infantry fire may be considered from two points of view, viz.: the effect on the enemy of a single projectile, and the effective hit in itself.

1. THE EFFECT OF A SINGLE PROJECTILE ON ANIMATE TARGETS.[124]

During the Russo-Japanese war the contending parties used the following small arms and projectiles:

The ballistic qualities of the Arisaka rifle were superior to those of the Russian arm, but the maiming effect of the two rifles was about equal. The striking energy of the projectiles was not sufficient in every case, however, to put a man out of action. The explosive effect produced by bullets striking interior organs and bones at short ranges (within 500 m.) was more evident in wounds made by the 8. mm. than by the Arisaka rifle.[125]

At mid ranges the wounds were generally of a mild character, unless produced by tumbling bullets.[126]

Experiments prove that a projectile will tumble if it encounters varying resistance (for example, if the projectile strikes an obstacle, even if that be only a twig) or if it penetrates materials of different density (for instance, if, in penetrating a body, it strikes first upon a fleshy part, then upon bones). In the last mentioned case the bullet will frequently tumble in the body. If a projectile be fired through a series of boards, placed at intervals, it will tumble in the second board, or if not there, then certainly in the third board. Projectiles which ricochet on the ground before penetrating a human body change their form more or less, according to the character of the ground on which they ricochet. As the jacket is frequently torn, thus exposing the leaden kernel, wounds may be produced which will equal those made by explosive bullets.

The striking energy of the projectile is sufficient to perforate two men at 1200 m. From experiments made with the Lebel rifle on corpses, it appeared that the projectile passed clear through 5 bodies at 100 m., through 4 bodies at 400 m. (even when large bones were struck) and through 2 bodies at 1200 m.

In the Russo-Japanese war wounds were distributed as follows, on a basis of 100 hits: lower limbs, 39.5; upper limbs, 25.4; abdominal region, 16.5; chest, 15.5; spinal column, 15, and head, 11. Flesh wounds are generally slight. This is due to the fact that the hole made by the bullet is small, that the exterior flow of blood is insignificant, and that the wound rarely becomes infected. Projectiles remain in the body now much more rarely than in the past.

The central portion of marrow bones is frequently splintered by projectiles, while thicker flat bones (shoulder blades) are cleanly perforated.

Unless a tumbling bullet or a splinter of a bone penetrates the lungs, chest wounds appear in much more favorable forms than in past wars.[127]