iechmca.1 Trecc-rise, On Mobile, tfrnllerv Find Art's D /e Oper'arfion^ . TECHNICAL TREATISE ON MOBILE ARTILLERY AND ARTILLERY OPERATIONS BY THOMAS McLEAN JASPER B. S., University of Illinois, 1910 M. S., University of Illinois, 1911 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of CIVIL ENGINEER IN THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS 1921 \ 3 l\ UNIVERSITY OF ILLINOIS THE GRADUATE SCHOOL APRIL 19, 19fil I HEREBY RECOMMEND THAT THE THESIS PREPARED BY THOMAS MCLEAN JASPER ENTITLED BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE PROFESSIONAL DEGREE OF CIVIL ENGINEER Head of Department of CIVIL ENG INEERING. Recommendation concurred in: Committee *“» * f ' ( : r% *\ (.> V/iW .JX- CONTENTS Page Introduction 1 Early History of artillery 3 General Type of Artillery Used by Different Ar- mies at the Beginning of the War ... 10 Light Field Guns 10 Light Field Howitzers 11 Heavy Field Guns 11 Heavy Field Howitzers 11 Mortars 11 Ammunition 14 Propellant Shell Shrapnel . . . High Explosive Gas shells . . Smoke Shells Incendiary Shell Star Shells . . 14 lb 16 17 19 SO 20 £0 Guns, Howitzers, Trench Mortars £1 Guns and Howitzers £1 Trench Mortars £4 Airplane Bombardment, Anti-Aircraft Bombardment and Anti-Tank Guns £b airplane Bombardment .... £5 anti-aircraft Bombardment . £6 Anti-Tank Guns £8 Future Development of artillery ....... £8 Trench Mortars 3 £ Anti-Tank Guns 3£ anti-aircraft Guns 33 Special Engineering Problems in Dealing with Major artillery Operations 3b Tr iangulat ion, Mapping, and Battery Surveys 3b artillery Register 41 Locating Hostile Batteries and Engaging Them Without Direct Observation 44 Flash Spotting 47 Sound Ranging 48 Construction of Gun Pits and Ammunition Dumps. bl Digitized by the Internet Archive in 2016 https://archive.org/details/technicaltreatisOOjasp 1 TKCPKIGAL ThiSATIbB OK MOBILE lihTlbLIA'.l AKD ARTILLERY OPaRATIURS IRTRODUCTIOR The following treatment of mobile artillery operations is ■undertaken for four purposes, namely: (a) To endeavor to collect together such of the experience of artillery operations as was generally understood prior to the Great War. (b) To outline the development in artillery operations that have been evolved during the Great War. (c) To outline, in general, the direction which develop- ment in artillery is most likely to follow. (d) To outline some special engineering problems which apply directly to modern artillery operations, some of which are directly applicable to civilian engineering purposes. Artillery has had an increasing part in the operations of armies of the world since as far back as the middle of the fourteenth century. Prior to this period, mortars and explosives were used by men of armies as part of the infantry units, and their duties were chiefly to create diversion for the enemy and to distract him from his main objects, the principal purpose be- ing to affect the morale of his troops. Guns were used in field operations as early as 1314. Prior to this period, gunpowder had been used as a filling for bombs, and a record of a very early B.C. use of a glass sphere filled with exposive is available, bince the year 1450, the real development of artillery as it is known today has been brought about. This development has been greatly assisted by the forward movement of science, until today in war the artillery is the most technically involved arm of any service. Especially is this true from a tactical point of view. It is true that the employment of artillery in warfare is limited to the type and up-to-dateness of the weapon used, and also to the supply of such weapons and ammunition for them. Al- so, in large measure, it is limited to the training and employ- ment of the personnel. The writer wishes to say nothing here which will detract from the glory and self-sacrifice of infantry units or engineer units which, during the first part of the Great War, literally made of themselves a wall of humans and offered themselves as a sacrifice to protect the nations and to Save the tactical situ- ation; neither would he compare the later work of the infantry under the support of artillery, with plenty of ammunition, so as in any way to minimize the necessity of their full employment in order that complete success might attend the efforts of the tac- tical commander. He simply wishes to point out that the artil- lery, as employed during the Great War, required a combatant personnel of the most highly trained kind, where organization and co-ordination were developed to the highest degree. This treatise intends to have very little to do with the design of Runs, howitgers, mortars, and ammunition, and there- fore very little will be said about them. It is intended, how- ever, to outline the growth in importance of artillery operations, roughly from its inception, but more particularly during the Great War ; ana, if possible, to outline the direction in which such growth is tending. , - • f 3 EARLY HILT OR Y OR ARTILLERY In the earlier days of artillery operations, special trains of artillery were raised for each war. It is obvious that such a procedure did not make for a highly trained c~nd efficient series of units, because of the fact that there was little continuity in the service from one war to another; and, in consequence, artil- lery operations assumed a very minor portion of the tactical value of an army during this period. This was due, in large measure, to the difficulty in transportation, to the lack of training of the personnel, and to the lack of power of the particular weapons in use. To throw a hundred-pound shot one thousand yards was a great achievement in warfare, and was not accomplished until about the middle of the seventeenth century. Prior to this period, the enemy's cavalry could, if uninterrupted, render useless the ar- tillery of an army in a very short time. Today, a battery of field guns, if supplied with ammunition, can protect its ow : n front against any type of attack, and, with the aid of the lighter machine gun equipment for flank protection, is practi- cally self-sustaining. About the year 1600, record is obtained of the average range of cannon, being less than one thousand yards. Loon after this time, however, certain experiments were made with gunpowder, ' and, in 1646, a muzzle velocity of 1140 feet per second was reached. Since, in the earlier employment of artillery, very little tactical value was obtained from their use, the training of personnel assumed very little importance. Prom the time of obtaining a muzzle velocity of over 1000 feet per second, the development of artillery was assured as an arm of considerable 4 tactical value ,lxifc the difficulty of transporting ordnance and ammu- nition and the slowness of loading the pieces still kept it as a minor arm. The training of the gunner, however, became of great importance, and from this time dates a drill procedure which tended to increase the speed and accuracy of artillery bombard- ments. The increase in muzzle velocity in 1646 was due to the strengthening of the propellant used. This necessitated a heav- ier and stronger piece, so that what was gained in muzzle veloc- ity was in a measure lost in mobility. The Civil V/ar of the United states, coupled with the Crim- ean and Indian Wars of England and the Franco-Prussian War, de- veloped the use of artillery to a degree unprecedented before, and, growing out of these operations, we have the modern breech-loading guns and howitzers. Luring the period of transition, breech and muzzle loading guns were alternately advocated. The test of the modern weapon came when the hussic- Japan- ese War was fought, where the speed and power of the artillery made itself of major tactical importance in warfare. Today the artillery is the heavy-hitting complement of the Army, and, during the Great War just passed, in co-operation with the development of the aeroplane, it has assumed a tactical importance of the greatest value. The technical consideration so that a close liaison between the artillery of today and the flying service may be obtained, make it imperative that the ar- tillery personnel should be selected with the greatest care and trained with the utmost intelligence. Between 1646 and 18b0, roughly, the development of ar- tillery was mainly confined to the improvement in drill, or the , , - . , - , • f ■ . 5 service of the piece, to the increase in strength and kind of ma- terials used for ordnance, which allowed a relatively lighter gun, and to the improvements in the propelling power of powder. The im- provement in drill was mainly brought about by having permanently established artillery units, where greater attention was paid to the discipline and auxilliary equipments. The knowledge of the strength of materials which has been developed mainly since this period was, however, greatly extended in the early nineteenth cen- tury. Luring the Great War, it has come to my knowledge, however, that in Sussex, England, cast iron cannon were made by Baude & Collet in 1545, and in the Library at Maresfield Park, a history of Sussex collected by its former owner, named Shelley, contains mention of foundries operated in Sussex much earlier than the date given above. An idea of the development of the strength of pro- pellants for guns between these two periods can be obtained by a study of certain available records. "The Art of Gunna’y," pub- lished in 1647, by Master Gunner Lye, gives the following data: n A six-pound shot, with a charge of three pounds of powder and a gun elevation of five degrees, obtained a range of 703 yards . n In 1856, at Shceburyness , a record of tests showed that a six- pound shot, under the same conditions, with one and one-half pounds of powder and one and one-quarter degrees gun elevation, attained a range of 688 yards. In other words, since 1647, with the use of one-half the weight of powder and one-fourth the gun elevation, the same weight of shot attained approximately the same range, - which indicates that the propelling power of pow- der was increased about eight times between 1647 and 1856. Be- tween the years 1850 and 1886, the muzzle-loading and breech- ■ 6 loading guns alternately were advocated by different government s. This controversy ended mainly due to the fact that 1886 marks the period when black powder passed out of use as a propellant for military guns, and also to the fact that the shape of shells had been so considerably modified that the elongated shell with driv- ing band gas check had superseded all others. With the passing of black powder as a propellant and the adoption of the breech-loading weapon, we had practically what the Great War was started with in the form of guns and howitzers. The development of the value of artillery between 1850 and 1886 was largely due to increased mobility, the training of personnel, and the use of rifling in guns which gave the shell a tw’isting mo- tion. From 1886 until immediately preceding the war, the strength of materials, the self-contained recoil mechanism which decreased the strain on gun carriages, and the increase in the power and efficiency of the propellant, were the- main directions of development. As an instance bearing out the growth in importance of artillery: At the Battle of Blenheim, 1704, the forces under Marlborough were 56,000 men and 51 guns, while the French had 60,000 men and 61 guns, or approximately one gun per thousand men. At the Battle of Austerlitz, 1805, the proportion of guns to men was one gun to 400 men. During the Civil War, the aver- age proportion of guns to men used in several engagements w ; as about one to 300,* , During the 'Bus si o- Japanese War, the aver- age proportion of guns to men was one to about 300, while at the beginning of the Great War, the proportion of the field guns, irrespective of heavier pieces, in the different 7 armies on the Continent were as follows: Belgium, one gun per 270 rifles; France, one gun per 210 rifles; Germany, one gun per 156 rifles; Great Britain, one gun per 146 rifles; Italy, one gun per 290 rifles; Japan, one gun per 240 rifles; Rouman- ia, one gun per 250 rifles; Bussia, one gun per 230 rifles; United States, one gun per 300 rifles; Austria, one gun per 310 rifles. During the war, however, this proportion was raised until an average of one gun per 85 rifles was used at times, and this in part shows the importance in the growth of artillery auring the last two hundred years. Very little has Been said about the ammunition used by the artillery during the earlier history of artillery opera- tions. This, however, has had a very important part to play in the value of artillery operations, and it is due to the de- velopment of ammunition, more than any other one thing, that changes in the use of artillery have come about during the Great War. In addition, heavy artillery has been used in greater quantity thu-n ever before, and this has been brought about because of the desire of using heavier projectiles. The design of the shape and stability of projectiles has had a considerable bearing on the development of artillery opera- tions. The earlier shapes were chiefly round shot, and con- sisted almost entirely of solid pieces of metal. The next step was to make round shot hollow and fill them with explosives, which could be exploded by the burning of a time -fuse. During the earlier part of the nineteenth century, Colonel Bhrapnel of the British ^rmy invented a shell which, 8 in modified formulas lasted to the present day. Grape shot, case shot, chain shot, and "bar shot have also been used from time to time, the name indicating the type of construction. The introduc- tion of rifling in guns brought into use the elongated shell, which had the effect of decreasing the weight of the gun for the same weight of shell used. This had a very marked effect on the mobility of artillery, and, in consequence, on its usefulness. Prior to the introduction of breech loading guns, some form of stud or grove was necessary in the shell, in order that it might engage the rifling of the gun when inserted in the muzzle. With the introduction of the breech loading piece and the ^'ixed cart- ridge case in the smaller guns, the necessity for grcowlng the shell or adding studs was done away with, the solid driving band was introduced, and the speed of serving the gun was brought up to the present maximum rate. This rate has increased to the max- imum of what the present field gun can stand with safety without some cooling device being employed. Parallel with the changes in the exterior shape of the projectile, large changes were made with reference to the gener- al interior contents of it. Gariy in the history of shell design, hollow spheres were made which were filled with black powder and sometimes with scrap iron. With the use of the elongated shell, together with the rifling of the piece and the application of bhrapnel's invention to them, the shape and purpose of the modern field-gun shrapnel shell had been very little changed up to the beginning of the late war. Prior to the invention by bhrapnel, shells were filled with black powder, and depended on the explo- sion of the shell and the damage done by the fragments. . ■ . . , , ( » « ► 9 The development of the explosive— filled shell kept pace w ith the invention of explosives. When the French, in 1886, adopted nitro cellulose as a propellant, it gave a great impetus to ex- plosives, and from then on, explosives suitable for the interior of shells were closely studied and many new kinds worked out. About this time, also, General Rodman, of the United States Army, did a considerable amount of work in propellants which helped greatly in the developments then brought about. When Lyddite, or some other form of Picric acid, was first used, its effect was supposed to be such that no life could exist within 50 yards of the explosion, so great was the detonating effect.' This explos- ive, or some slight modification of it, was used in high explosive shells at the beginning of the war by almost every great nation. Nothing has been said in this thesis as to the develop- ment of gun carriages. Until the last twenty years, the gun carriage had been changed very little, with the exception of the size of wheels and the strength of the carriage to take care of the larger muzzle velocity developed in the piece. Since about 1895, the self-contained recoil mechanism of the modern gun has been developed, and no one thing in gun-carriage construction has had a greater effect on the accuracy and rapidity of the ser- vice of artillery. Prior to this, the eun, properly attached to its carriage, was placed on a ramp, which consisted of an upward slope in rear. When the gun was fired, the shell went forward, and the gun advanced to the rear up the ramp, with more or less uncertain gait. The tendency of the ramp w as to restore the piece to its original firing position, at the beginning of the 10 Great War, most of the different countries had their campaign ar- tillery equipped with some kind of recoil mechanism. The pre-v/ar system, as used by the British, German, Austrian, and American artillery, comprised, in the main, a spring recuperator with an oil buffer. The French, however, used an air recuperator 'with oil buffer, which made the service of the gun sc equipped very rapid, due to the fact that the piece would recoil and recover with the least displacement of the gun carriage after the first round had been fired, due to more perfect control of the applica- tion of the retarding and recuperating forces, and also to the fact that the heat developed in discharging the gun tended to im- prove operation rather than to put the gun out of action, as is the case of the spring recuperator. GENERAL TYPE OF ARTILLERY USED BY DIFFERENT ARMIES AT THE BEGIRDING OF THE WAR A general description of the artillery used for field operation by the different armies at the beginning of the world war may be summarized under the following five general heads, as shown below: Light Field Guns . Calibre 2.5" to 3.5". General type; spring recuperator, hydraulic buffer. Piece varying from 20 to 35 calibres in length, firing high exposive and shrapnel shell, and being capable of carrying out a sustained bombardment of about 6 rounds per gun per minute, with occasional rare bursts of 10 rounds per gun per minute. Weight of shell from 12 to 25 pounds. Primarily designed against troops in the open or with slight pro- tection. The exception to the above is found in the French 75 m.m. which used an air recuperator. 11 Light Field Howitzers . Calibre 3.0” to 5”. General type; spring recoil, hydraulic buffer. Piece varying from 10 to 18 cal- ibres in length. Using high explosive and shrapnel shell, capable of carrying out a sustained bombardment of about 4 rounds per gun per minute, with occasional rare bursts of 6 rounds per minute. Weight of shell from £0 to 60 pounds. Primarily designed against troops in the open behind crests of considerable height or in trenches where high angle fire is necessary. These were also used for light demolition operations. Heavy Field Guns . Calibre 3.5” to 6". General type as above, firing shells up to about 100 pounds, and used primarily for bombarding concentration points and railway terminals. Heavy Field Howitzers . Calibre 5" to IE”. General type as above, and firing shells up to 750 pounds. Used mainly for field fortifications and very strong points. The lighter pieces of the group used for counter battery work. Mortars . The Austrians had built some very heavy mortars, which were used to reduce the forts at Maubeuge and Leige. Ho trench mortars were used at the beginning of the war. The history of the Great War can be traced tc a large ex- tent in the artillery development between 1914 and 1918. The quick advance of the German army, supported 12 "by a large force plenteously supplied' with artillery and ammuni- tion, opposed at first "by forces with relatively little artillery and ammunition, the gradual proportional increase of the artil- lery and ammunition of the Allies and the uses to which artillery was placed, until the artillery became extremely numerous in pro- portion to the other arms, and ammunition exceedingly plentiful. During the period of transition, the Allied infantry and artillery forces carried out an extremely difficult task, and, as has be- fore been mentioned, did a work which has never before been sur- passed. The tactical advantage, however, nearly always lay with the force with the preponderance of guns and ammunition. The general artillery development of the allies during the war was, first, to manufacture more ammunition. This burnt out the guns. The next step was to build more guns of the pre-war type and to bring into service certain types considered obsolete , since no time was available for d-eveloping new types. The next thing was to protect the guns from hostile counter battery work, be- cause, as soon as guns and ammunition became more plentiful, the enemy's attention was focused on gun emplacements and counter battery work, and the excessive pressure was taken off the in- fantry. The next step was, (and this after trench warfare had become necessary) , to build gun pits which would protect tne guns and men from excessive bombardments. As the guns became more numerous, the co-ordination of the work they w;ere to carry out became more and more difficult, and communications between batteries and the troops they were supporting assumed greater importance. These conditions developed a system of trench raid- ing with the assistance of the artillery at night , and later on by day, in which communications usually suffered and co-operation more or less failed. This led to extensive telephone and Morse systems of communication. The next step was the trench mortar in various forms, which cut down the communication systems necessary hetween infantry and supports in time of raid, and allowed the front line to be self-sustaining in minor engagements. Hand grenades and rifle grenades, all depending on the supply of am- munition other than small arm were used in numerous forms. The development of the gas attack and the screening of troops by smoke by the use of shells was the next step. During the whole of this period, the types of ordnance used had not been materially altered, vvith the exception of the construction of trench mortars, but the ammunition had undergone a very great change , both in kinds in use and the proportion of each kind used. Ho extensive change could be attempted in gun construction for fear of retarding the supply, although certain improvements were clearly indicated by the experience of w : ar con- ditions. with the development of the tank came a construction of the light anti-tank infantry gun and a change in the use of field guns to repel tank attack. At the beginning of the war, the aeroplane was used en- tirely as a scout, but as aeroplanes became more numerous, larger and larger numbers were assigned to the artillery service. This service developed from plain observation of artillery by artillery observers in planes to a general direction of artillery work in the back areas from the airplane. The next step was to carry out a considerable number of bombardments by using aeroplanes equipped with bombs under direction of commanders trained in artillery - 14 demolition work in areas much farther "back than could he carried out by long range artillery, and this developed the airplane bomb- ing service, which is undoubtedly destined to replace long range artillery in warfare. With the increase in intensity and amount of counter bat- tery work, enemy batteries became more and more careful in select- ing positions, and the development of the flash spotting and sound ranging sections were brought about, which, when developed to their highest point of efficiency, allo?ved batteries to be- ranged on known targets at any time of the night or day, and, in addition, permitted the location of careless batteries. Toward the latter part of the war, guns underwent some changes. British field gun carriages were reconstructed after the French plan of air recuperator buffer, and a type of screw breech which was invented by an American engineer was adopted for the guns. A considerable amount of the transportation formerly car- ried out by horse-drawn vehicles became motor driven, bervice tank gun carriages were tried out, and in certain cases put into operation, and proved successful in rapid movement warfare. AIvDSfUHITIOM Ammunition is divided into two parts: the propellant and the shell with charge.' Propellant . The propellants used by nearly all artiller- ies are very similar, and are composed, in general, of varying proportions of nitro-glycerine or nitrocellulose. Both types of propellant are made from guncotton, and the action of each is ' . • , ’ . 15 quite similar. Nitro-glycerine has a higher explosive temperature of the two, and tends to more rapid wear and tear of the piece. The war did not bring about any material change in the composition of propellants. The normal explosive action with propellants con- sists of progressive burning. Each layer of the propellant is raised to its ignition temperature by heat directly transmitted to it from the layer preceding it. Because of this action, the pro- are pellants A callea "low explosives", which means that the rate of action is relatively slow. Shell . Shells are divided into many classes, such as Shrapnel, High Explosive, Gas, Smoke, Star, and Incendiary. Gas shells are subdivided into Tear Gas, Poison Gas, Burning or Blis- tering Gas, and Sneezing Gas. Shrapnel shell, or a similar form, was used by nearly all of the armies at the beginning of the war. The British used a large proportion (about 90 per cent) in their field guns. The French and Germans used a larger proportion of High Exposive. By the beginning of 1915, the British used 75 per cent Shrapnel and £5 per cent high explosive, which showed that for trench warfare high explosive was gaining in favor with them. The Germans produced a shell similar to the ahrapnel, but with ex- plosive mixed with the bullets; this, however, proved very un- satisfactory. During 1916 and 1917, high explosive gained ground with reference to the proportion used, and shrapnel became less used, but in 1918, shrapnel came back again as the open warfare shell. _ — To The bhrapnel shell is made up as fol- lows (see Figure 1): The container A is made out of a rela- tively thin shell which acts as the carrier of bullets. A time fuse is set so as to send a flash down the tube C when the shell reaches black powder, which is used for two purposes, - one to propel the bullets out of the shell, and the other to give a thick, white smoke so as to locate its burst easily. The shell case is supposed to be strong enough to resist being broken up, so that it acts in a manner similar to a shot gun as soon as it reaches the desired range. The effect is as in Figure 2. The German Government adopted, in 1915, a shell containing numerous bullets with high explosive melted between the in- terstices. The burst was about the same height as ordinary shrapnel, but the bul- lets seemed to have very little penetrating effect. Instead of the bullets coming down as a hail shower, and as soon as the shell had exploded, they seemed to take about 15 seconds to finish dropping, and were scat- tered over an area of about 80 yards in diameter. Following this, they adopted a segmented shell filled with high explosive on the inside of the inner segment. The shell was built up of three lay- ers. The outside case was segmented similar to the Mills bomb but Bo l lets \ \ \\ \ Figure 2 on the inside surface, and the inner two cases segmented on the , t , . - f . . 17 outside surface. This was exploded in air, and had a varying ef- fect, depending on the height of hurst. In general, many of the pieces fell after about 10 to lb seconds, with very little effect because of loss of velocity due to air resistance, later, they adopted the shrapnel as used by the other armies. The shrapnel shell has held its own as the light field gun shell for open war- fare. The greatest improvement has been the adoption of a mechan- ical time fuse in certain armies, which will enhance the value of the shrapnel shell considerably and allow ranges for shrapnel use which could not have been maintained with the old-type time fuse. The High Explosive Shell is construc- ted (see Figure 3) with a relatively thick wall inside of which it is filled with a high explosive. The high explosive used by the British was Lyddite; by the French, Melenite, and by the Japanese, Bhimose. These are, in fact, simply Picric acid, and the fancy names used are merely camouflage. Tri-nitro-toluene was the high explosive used by the Serbians. The production of such high explos- ives increased very rapidly during the w ; ar, and. Picric acid could not be obtained in sufficient quantities to supply the demand, and tri-nitro-toluene was used to a much larger degree than Picric acid. It is much easier to manufacture on a larger scale, and possesses several distinct advantages, the main one being that it is less dangerous and more easily handled. By one army alone, during the war, 69,000 tons of Picric acid and £60,000 tons of tri-nitro-toluene was used, principally for the filling of shells. High explosive differs from low explosive mainly in the rate of the explosion. In low explosives, a progressive reaction prevails, while in high explosives it is practically instantane- ous. The use of high explosive shell at the beginning of the war w r as chiefly for demolition purposes or for destructive bombard- ments against fortifications. The French used it as an air burst shell, and the Germans developed the same idea early in the war. The British, however, practically never used it as an air burst shell, except for wire cutting or for aircraft bombardments. Wire cutting developed the graze fuse, and the effect of the graze fuse with high explosive recommends its use for open warfare; but where the ground was sufficiently hard and the trajectory slope suffi- ciently small, delay action fuses gave the best results in open warfare (see Figure 4). The heavier guns used high explosives with delay actionffuses against heavy fortifications and concen- tration points, the delay action in this case being such as to allow time for penetration. Figure 4 V , , . 19 Four fuses have survived the war for use with the high explosive shell: the graze fuse, the delay action fuse, the plain percussion, and the mechanical time fuse for aircraft straffing. The first two are destined to he of great value against troops in the open, and the second for demolition also. The third type of fuse was what the war was started with. Gas shells , as known today, were used for the first time during the war, and their development h~.s been largely due to the unsatisfactory use of gas from projectors and to the desire of using it behind theaiemy's lines. There were four types of gas shell in use at the time the armistice was signed, viz.,- (a) Lachrymatory, or tear gas, (b) Lethel, or poisonous gas, (c) Vesicatory, burning or blistering gas, (a) sternutatory, or sneezing gas. The first two kinds were used principally, although vesicatory and sternutatory gases were used considerably tow r ard the latter part of the war. The chemical formula for these gases are carefully guard- ed, and it is not in the nature of this thesis to tabulate here such as I possess. Lethel gases fall into two groups, - light and heavy. The heavy gas is used when an attack is not to follow, and the light gas when an attack is pending or when the atmospheric conditions are satisfactory for their use. In using chemical gases, great care is necessary in order to utilize the atmospheric conditions to the best advantage. The shell is similar in con- page 17 struction to the high explosive (Figure 5) , but with thinner walls , . . 20 and with a filling of the gas either in solid form or as a liquid. An exploder is usually provided which will generate sufficient heat to liberate the gas for the effect desired. The graze type of fuse is the most useful for the distribution of gas from shells. Smoke shells are similar in construction to the gas shells, and are usually filled with white phosphorous, which, when burst with a sufficient exploder, gives off a dense, white smoke. This shell is destined to be used very considerably in the attack for screening infantry against machine guns. The best effect is ob- tained with a time fuse w ! ith low burst, either this or a graze fuse. The incendiary snel l is similar in construction to shrap- nel, with the bullet space filled with thermit or something simi- lar. The best effect is obtained with a time fuse which is set to burst very near the ground. When burst under such conditions, the effect is very good indeed. Green timber and grass are set on fire by its use. It also forms a fairly effective smoke screen. Star shells are similar in construction to the above, with bullet space filled with stars or lights. They are used at night, usually as signals, and with time fuse. The war development of shells has been to add all of the above types except shrapnel and high explosive to the list, and has considerably extended the use of high explosive by the addi- tion of the graze and delay action fuses. It hc,s also extended the use of shrapnel and high explosive by the development of mechanical time fuse. £1 GURb, HOWITZERS, TREE GH MORTARS Guns uiid howitzers . During the war, ordnance changes were very few, due in large measure to the dangerous proceeding of chang- ing old types for better pieces and in consequence cutting down the supply to the forces. An instanc e of what is meant is shown in the partial equipment of the United states troops with modified Enfield rifles, because plants were available in the United States for turn- ing out great numbers of them, while facilities were lacking for man- ufacturing the United States service pattern in sufficient quantity. So with the general types of ordnance in use at the beginning of the war. Toward the end of the war, however, the British had adopted the air recuperator in most of their mobile artillery. They had also adopted the single movement screw breech and a trail to their light gun carriage which allowed the field gun to increase its elevation, and certain types of heavy guns were mounted on railway mountings. It was noted early in the war that the German field guns and how- itzers seemed to wear less rapidly than was the average case with the allies’ field guns and howitzers, as tne groves on the driving bands of shells due to the rifling always seemed more distinct. The life of field ordnance before the war, measured in shells consumed, was considered to be about one fourth of what was actually fired during the war. This, means, however, that the guns and howitzers were allowed to wear to a point which was previously considered in- accurate and dangerous, an interesting outgrowth of such longer life has been the improved range drum in some types of gun, which permitted muzzle velocity corrections to be automatically adjusted for. . . , 22 After-war design, however, will he sure to take into con- ana howitzers, sideration the motorization of guns^ either hy having a tractor in place of horses, or hy having a gun mounted on self-propelled caterpillar or ordinary wheel mounts. From many tests held dur- ing the war, it is considered that for light artillery the cater- pillar is the only prime mover which can adequately replace a team over rough or soft ground, and in order that an ideal gun mount caterpillar may he designed, it must conform to certain specifications, as follows: (a) It must have a platform which is relatively low, so as to give it the maximum stability. (h) It should have a traverse of at least 60 degrees, preferably by having a pedestal type mount for the gun. (c) It should he able to he operated so as to approach the enemy, gun muzzle forward or to retreat with its gun muzzle to the rear, with the possibility of its fighting personnel be- ing protected. (d) It should he able to he fired from the traveling position, without further ground support, if necessary. (e) Its maximum speed should not he less than ten miles per hour. (f) It must he able to transport a reasonable amount of ammunition. (g) Caterpillar ammunition caissons will also he neces- sary. Tests that have already been made with caterpillar mount- ings have shown conclusively that a brigade similarly equipped 23 needs about 40 per cent as much rail train space, and will require about 35 per cent as much shipping weight for transportation. Motorized artillery will cover about three times the distance cov- ered by horse-drawn artillery in a day, and can keep it up contin- uously. In addition to this, the supply transportation necessary for motor prime mover fuel will be considerably less than horse fodder. It is not suggested that this change be made until a good type of carriage has been designed, and it may even then be wise to motorize slowly. A considerable opposition will exist to motor- izing artillery, and especially the lighter types. The writer him- self served four years of the war with a horse unit, and knows the faithful and consistent w/ork done by them. The advantages of the motorized equipment are briefly as follows: (a) It requires less personnel to operate, and is less vulnerable . (b) The horse, when once wounded, becomes an encumbrance and decreases the available tractive power. (c) The caterpillar can negotiate all ground possible with horse-drawn batteries. (d) Less display and therefore liable to less attention from the enemy. (e) Less road space required. (f) Practically immune from machine gun fire and there- fore from airplane attack. (g) Requires far less supplies to operate, but necessi- tates a more highly trained personnel if remount and veterinary personnel are not considered. ■ — _ __ 24 2 x v> V V Trench Llortars. - Although^ mortars v/ere used very early in warfare, they were not considered as part of the equipment of a modern army at the beginning of the war. The trench mortar may he considered as a long range bomb thrower which possesses the following characteristics: (a) Lightness when considering the weight of shell fired. (b) Simple in operation, not requiring the complicated drill of artillery. (c) High angle fire, allowing it to be fired from a trench or well-protected cover. (d) The effect of shell against trenches and earthworks very great. (e) Cost of and difficulty of production less than mo- bile artillery. The trench mortar is not expected to take the place of field guns and howitzers, but can be best described as an auxil- liary which can be made as mobile as infantry with very little construction difficulty. The general direction of future devel- opment of trench mortars is a modification of a motorcycle side car arrangement for the lighter trench mortars, and a whippet tank for the heavier types. In the United btntes tests on equipment for the motor- ization of artillery has been carried very far indeed. Very little has been done, however, on trench mortars which should accompany infantry. This, however, is probably due to the con- sideration that future Wars will be wars of movement rather than of trench warfare. Yet if probable future wars are to be - ■ ■ 25 considered, and a certain period of time is to be given, such as is at present advocated by many, before actual fighting begins, the tendency will be for trench warfare to be determined on by the weaker power, which will compel the stronger power to resort to the same method as was adopted in the first three years of the past war. AIRPLANE BOMBARDMENT , AN T I -a IR C RAF T BOMBARDMEIIT , AMD ANTI-TANK GUN b Airplane Bombardment . - Little has been said of the development of bombardment by aircraft. Such methods were developed entirely during the war by air forces. It was undertaken by that part of the air force whose duty it is to act in the capacity of long range guns and to destroy strong points and concentration points be- hind the lines. The value of such equipment may not be under- estimated, and the economy and accuracy of such methods are far in excess of long range bombardments with heavy and cumbersome guns, which requires a large amount of transportation in a war of movement, and, in fact, are unable to be employed with any- thing like the tactical value that their trouble and expense should demand. In a war of movement or trench warfare, where roads are of paramount value for the movement of troops, and where roads are often few and badly constructed, the squadron of bombarding aeroplanes is worth several heavy batteries, in- asmuch as it can have a greater range of operation, can select its targets of military value, and can do its work in a manner tending to protect the lives of the non-combatant population. . . ♦ * £6 The personnel engaged is very much less in proportion to the mil- itary value obtained. The hitting of a target from sometimes two miles above the ground calls for a bombing sight which would need descriptive details far beyond the scope of this thesis. The gen- eral principle, however, is that of locating the spot on the ground over which the plane with the bomb is flying, setting the sights according to the relative height of the plane and the ground speed of the plane and then maneuvering for position. The results obtained were very good indeed, but it will require care- ful training of the personnel in order to operate to the best ad- vantage. Care must be taken, however, that the plane is flying on an even keel, and that it is not increasing or decreasing speed immediately prior to the release of the bomb. Flying developments are of greatest interest to the ar- tillery. The helicopter has been experimented with since early in 1915. This machine, which depends on propellers set at dif- ferent angles, will allow an air machine to rise almost vertical- ly from a position and to alight in a very small space. At least one nation has spent considerable sums in investigat ing such a possibility, and since such investigations were started in 1915 and are still carried on, it would lead one to believe that con- siderable value is attached to such an arrangement. The chief difficulty lies in stabilizing the machine in the air and to pre- vent it from acting as a top. Anti-Aircraft Bombardment . The best anti-aircraft weapon is the fast aeroplane itself, operated by an aggressive body of pilots and machine gunners. Anti-aircraft artillery has been de- veloped, however, and an anti-aircraft weapon, which comprises £7 bss&£ quick-firing guns for a range up to 10,000 yards and an angle of elevation of approximately 90 degrees has been very successfully used. The main difficulty, however, has been the fuse which will burst the shell in the air for this range. The development of the clockwork fuse has greatly enhanced the value of the anti-aircraft gun. The main difficulty is to find an automatic compensating sight which is sufficiently rapid to give good results. It must be understood that it takes a considerable time for the shell to travel from the gun to a point in the neighborhood of a plane. The plane is a fast-moving object, and can arrange itself after the shell has left the gun in a great many different positions, varying from a quarter to a half-mile from its gun sight position at the time the gun was fired. To get a direct hit requires a considerable amount of judgment and good luck. The anti-aircraft batteries have been mainly employed, therefore, in setting up bar- rages in the air and cutting off the hostile planes from their objectives and in herding them until the friendly airplane is in a position to deal with them. The psychological effect of a shell bursting in the neighborhood of an airplane tends to upset the equilibrium of any but the most fearless pilot. It is then that the pilot begins to realize that he is really in the air, and that he is a long way from friends. To persist in posing as a target is almost foolhardy, and is likely, although he gets through on his mission, to result in information of questionable value. The low-flying machine gunning plane is most difficult to handle, however. The best method of combating this is a machine gun well pivoted, or the quick-firing light field gun with muzzle burst r j 28 shrapnel. The greatest room for improvement in the anti-aircraft gun is in the sights and sighting arrangement, and a combination of range finder and compensating sights seems to be the direction in which the best results are likely to be obtained. The anti- aircraft gun should be as mobile as the light field artillery. Anti-Tank Guns . There is no doubt that the best practice in anti-tank gun construction may be followed from a study of the German method. The first development by the Germans was a rifle which could be operated by an infantryman w : hich had a calibre of about one-half inch, using an armor piercing bullet. The next de- velopment was to use certain light field guns which were placed in salient positions, but so arranged as to give a wide arc of fire. The development of the future will no doubt be a gun mounted on a fast -moving,//, light caterpillar, and using a pedestal mounting with a gun so balanced as to be readily handled. This type of gun and caterpillar is also the direction toward which the future light or field artillery seems likely to develop. The ammunition for such an anti-tank gun should have a hard nose, with either a base fuse or a percussion fuse contained immediately behind the nose. Flash spotting and sound ranging will be taken up as spe- cial engineering features, and will not be treated at this parti- cular part of the thesis. FUTURE DEVELOPMENT OF ARTILLERY The future development of artillery will be governed some- what by the political situation, and also by the attitude taken by the most militaristic and aggressive nation or nations. The , M . * . . . 29 successful organization of the league of nations or some similar arrangement will go a considerable way toward decreasing arma- ments. The organization, however, will he determined largely on the experience obtained in the war just passed and on the antici- pated character of the expeditions on which military forces are likely to be utilized in the future. In minor operations, the necessary artillery will be of the fast-moving type, while the heavier bombardments will likely be carried out by the use of air- planes. In major operations, the first stages will also have to be of a similar nature, but with a relatively greater force en- gaged. The campaign would probably open with airplane reconnais- sance with long-distance bombing designed to hinder concentration of troops. The strategical advance would probably be carried out by mechanically transported units of infantry with fast-moving tanks as scouts and motorized artillery in support. The trench system will not appear unless the weaker force wishes to gain time for concentration or training of its non-militari zed population. Until trench warfare has developed, very little use will be got- ten from guns of the larger calibre, and, in fact, little value v/ill be obtained from heavy artillery which is not possible in the bombing aeroplane, because of the fact that the heavier guns are not rapid moving equipments, and are therefore left far behind in a war of movement. The calibre of guns for field operation will therefore be determined by their mobility and usefulness. The gen- eral consensus of opinion during the past war was that greater shell power is needed. However, officers with considerable experience in the use of guns using different weights of shell are of the opinion that the quick-firing light field gun is the most useful . 30 weapon for general purposes because of the rapidity of its service and general handiness in directing its fire, and also because of its mobility. There are two distinct schools of development for mobile artillery, and they are parallel up to a certain point. One is to use bombing airplanes for long-rahge bombardments, and the other is to trust more to heavy artillery; while both advocate using light artillery for infantry support and ordinary artillery w-ork. The greater feasibility of either plan hinges on the accuracy of the bombing plane, which, with the development of the bombing sight, can be as accurate as the long-range gun when the length and breadth zone is considered, even when the gun is served with good airplane observation. The range of action of the airplane and the variation of the size of its bombs allows it to be util- ized for a much greater variety of purposes, while its mobility and readiness to serve without clogging the roads, which are so much needed for other tactical purposes, apparently makes it a much more economical and feasible weapon. The bombing airplane was intensely developed during the latter part of the war only, and the test of its usefulness was carried out at first by men who had had relatively little experience with bombardments. Its usefulness has been demonstrated, how r ever, and in the hands of an aggressive and scientif ically trained personnel, it has grec,t possibilities . The calibre of guns, howitzers, and trench mortars as used most consistently during the late war are as follows:- 31 Guns .. Weight of Howitzers Weight of Trench Mortars Projectile Projectile by weight of Projectile 3” 15# 4.0” 30# 10? 5 M 60# 6.0” 100# 50# 6” 100# 8.0” 200# 100# 150# At the beginning of the war, the following proportions of field guns and howitzers to rifles and machine guns were available in the four main armies: American ... 1 to 310 British ... 1 to 147 French ... 1 to 280 German ... 1 to 156 During the war, this was increased in certain sectors to 1 to 60, while the average was 1 to 120. During a war of movement, it is difficult to maintain such a large proportion of field guns and howitzers, and the number dropped to about 1 gun per 160 rifles. This latter proportion is about the maximum quantity of artillery that could economically be employed with the war-time method of transportation and with the concentrations of troops employed. With motorization, this proportion can be materially increased, or with a lesser cone entrat ion of troops the proportion of guns can be increased. With motorization,, the suggested proportion of artillery assigned to field operations per division of 15,000 rifles is as follows : 72 Field Guns 3 M calibre 12,000 yards quick firing up to 10 r.p.u 36 Howitzers 4" tt 10,000 18 Guns 5” 1 * 18,000 8 Howitzers 6” tt 15,000 6 Guns 6" tt 25 , 000 3 Howitzers 8” Tt 18,000 5 r . p . n It TT Tt ) . , . . , . , < 32 Trench Mortar s. In 1915, when raiding was practiced to a considerable extent, protection to infantry was obtained from the field artillery immediately behind the front in which such infan- try were located. Toward the latter part of 1917, this work in general was taken over by the trench mortar batteries, and this support could be carried out more intelligently because the mor- tars were on the spot and more accurate observation could be ob- tained. Luring the open warfare which immediately preceded the armistice, the lighter trench mortars were pushed forward with the infantry on improvised carriages. This is true of the mortars using the 10 lb. and 50 lb. projectile. The proportion of mortars used during the latter part of moving warfare was as follows: 2 per battalion; 10 lb. projectile; range , 2000 yards 2 per regiment; 50 lb. projectile; range, 3000 yards The large caliber trench mortars are necessary only when trench warfare has developed. Anti-Tan k G- uns . The guns used for anti-tank work will probably be the ordinary 3-inch quick-firing gun, and using a special projectile with armor-piercing nose. This is also the logical light gun to use for general purposes, and which will be located so as to take care of the tanks more readily in whatever part of the line they may appear. It is presumed that this will be the type of field gun used, which will be on a caterpillar base and a pedestal mount of some type similar to the small calibre guns on a ship. i£ ach field battery should be provided with a small proportion of armour-piercing ammunition. . ■ . . 23 For field operations, it is considered that the bombing plane will be sufficient to take care of bombarding the enemy's back areas and concentrat ion points. Anti-Aircraf t Uuns . The future development of the attack on enemy aircraft may be considered from two standpoints: (a) One requiring a very mobile gun in a position with the advanced line of troops to provide a screen or to put up an air barrage which will prevent hostile airplanes from crossing the line and to prevent reconnaissance . (b) The other requiring a very much more carefully trained personnel and a gun essentially designed for anti-air- craft straffing after the airplane has crossed the lines. This presents a gunnery problem requiring more accuracy and also al- lowing a less mobile type of gun with very accurate ranging devices. Problem (a) can very well be undertaken by a 5-inch gun, provided it is mounted on a caterpillar with a pedestal mount capable of an elevation of 75 degrees or more and a considerable traverse. This also outlines the ideal light field gun for gen- eral purposes. The sights necessary for high angle barrage are simple, and could be assigned to the ordinary field gun battery, together with sufficient long-time fuses. To successfully engage enemy aircraft so as to prevent his doing reconnaissance work be- hind your own lines, it is necessary to engage the target over or behind the enemy's lines. The expenditure of ammunition under such a condition may serve two purposes, i.e., create a barrage ■ . ' * J ■ . 34 front which prevents enemy aircraft from crossing the A line, and also create casualties to his personnel on the ground behind his lines. Problem (b) is one which demands the least expenditure of ammunition consistent with the object to be attained, and requires ranging devices which will place shell bursts uncomfort- ably close to the flier. If a shell can be burst in space at any designed spot, although during the time of flight of the shell the target may not have moved along the anticipated path, the target can at least be prevented from moving along the path which will result in its doing the most damage and therefore the purpose for which it came can be at least partially thwarted. The number of direct hits on airplanes by anti-aircraft guns dur- ing the war were very few indeed. This in large measure is due to the present cumbersome sighting arrangements, but the problem has recently assumed a less difficult possibility of attainment, and possibly will keep all but the most daring pilots from gain- ing their objectives, providing the anti-aircraft artillery are well organized. One thing should be understood in discussing large guns. It is unlikely that if sufficient frontier or coast defense guns are on rnilvray mountings that the whole of them on all the frontiers will be required for that particular purpose during the period of any particular military operation or series of operations, and therefore some of them can be spared for field operations. One can imagine, also, what would have been the ef- fect of the guns belonging to the forts of ilamur ana Leige at the beginning of the Great war if they could have been withdrawn after it became apparent that tactically their value was greater . U ' . F 35 elsewhere. They certainly could have proved much more difficult as targets if their position could have been changed; in other words, if railway mountings had been available for them. A fort gun fixed on concrete mounts can possibly do better work than when on a railway mounting against less powerful weapons. It seems very foolish, however, for such guns to be expected to com- pete with more powerful guns or guns very difficult to locate, whose positions may be changed after they have been located. SPECIAL ENGINEERING PROBLEMS WHICH COME UP IN LEAL IHG- WITH MAJOR ARTILLERY OPERATIONS Irisng ulation, Mapping, and Battery Surveys . In the early part of the war, although Prance and Belgium had been surveyed and mapped, it became necessary to have a new survey made of the probable battle areas so as to construct more accurate large scale maps. This w;as necessary because in Prance very few 1 areas had been accurately mapped on a large scale. These maps would never have attained the accuracy they did had it not been for the special needs of the artillery. The old French survey of l/80,000 was used and enlargements made at first, but map range, deflection angles, and elevations from such maps were very inaccurate. It is presumed that Prance was as carefully surveyed as was necessary for all practical, non-military purposes, but it became necessary to have a military survey made for the artillery which also was useful for all arms. 36 All mapping is based upon a network of triangulat ion; such a network is available in almost all civilized countries. In France and Belgium, at the beginning of the war, there were three inde- pendent systems of triangulation, - one French, one Belgian, and an international system. [The first really useful approach to a sufficiently accurate survey for the artillery was obtained by the guns themselves, and a description of the first artillery plat will here be given. It was soon very obvious that the original maps as- signed to the artillery were notoriously inaccurate. Che triangula- tion points, . such as churches and prominent windmills, were accur- ately located, however, and their co-ordinates known; and these were the chief landmarks used by the artillery, together with any other important points whose visibility from the batteries were good. The intermediate points were not accurately located, how- ever, and it became necessary to construct battery plats from fir- ing data, which were handed on from battery to battery. From these plats successful batteries located their position and proceeded to locate certain reference points which were used as aiming points, witness points, and calibration targets. The panoramic or dial sight was used by each gun as a transit, and the gun itself was used as the measuring device. In this manner the battery was able to bring accurate fire to bear, night or day, on any visible tar- get, but this was possible only after a complete registration by the guns on such targets. Tactically such a procedure was danger- ous, and resulted in an unnecessary expenditure of ammunition, - dangerous because it indicated to the enemy the location of hostile guns and also showed him whenever any concentration was in progress or any change of troops was occurring. « A register and a map plot was made of targets, which had the effect of mapping targets in the enemy country, (bee diagrams 1 and 2). This method was early suggested by the writer as a zone map and register for each battery, which was to be left in any va- cated position by the outgoing battery, but in case of a retreat it was filed with General Headquarters. This was adopted at head- quarters, but great difficulty was found in having it carried out in practice. Later, the so-called artillery zone board was con- structed by survey sections, which located the battery position and many points visible and invisble from the battery, buch lo- cations made by the survey for a battery , both by triangulation and by air photographs, were indexed and filed, so that at any future time a new plat could be supplied to a battery which, due to casualty of some sort or other, had lost its original plat. In addition to this, the surveys were used for bringing maps up to date. Here may be indicated a method for identifying activity of any sort by aerial survey. It was discovered that if successive photographs were taken of any particular area, and the negatives compared by superimposing one on the other and holding them up to the light, a very slight change would show up distinctly, whereas a side by side comparison of the pictures would require consider- able time and experience for the observer to locate the same changes. It is necessary that the negatives be approximately on the same scale. This method lends itself to several useful pur- poses, i.e. - (a) It is well known that certain rivers, for instance , the Mississippi, change their course considerably from year to 38 year, and a complete ground level survey is practically impossible. A week's photographic survey per year from an airplane would give the information on which could be based a more economic control of such a river. (b) Much of the forest lands of the United btates have not been completely surveyed. An aerial survey would give information which would be valuable in lumber controversies, and would also give the Forestry Service a useful and valuable means for controlling the lumber business. Such use of the air service would not only be good train- ing for future war aviators, but would serve a most useful purpose in time of peace in training observers in performing useful duties vdhich would require a greater degree of concentration, and which would also tend to complete a survey of the country, which is much needed . In addition to the two instances noted above on the value of air surveys, it becomes invaluable where triangulat ion points are easily located from photographs for ordinary surveys. It is necessary, however, that the camera used be perfectly vertical when pictures are taken. The battery survey became the most satisfactory method for locating positions, but it is one that cannot keep up with the demand of batteries in moving warfare. Every battery officer should be trained, therefore, in constructing an artillery board for himself, on which is plotted targets engaged. 4 , • c Diagram 1 Buttery Lone Map Target Mo. Range Yds. Deflection from Zero Line Angle of ; Remarks bight 1 960 6° R ' 15' E Hindenburg Junct. 2 950 6° L 25' E Junct.of 4th & 5th Trench 3 1300 5° Ft 35' E belwaban Redoubt 4 1150 12° R 20' E Trench X 5 1100 10° R 10 1 D Men of Pottage Junct Diagram 2 - air photograph showing typical patchwork of cultivation dnd roads (Elevation about 20,000') 40 The artillery board made for a particular bat- tery position consists of a zinc covered board on which is pasted a piece of plain paper. Lear the bottom of the board is located the position of the pivot gun of the battery, and the line marked n xo" represents approximately the center line of tie zone to be covered by the bat- tery. The necessity for such a board lies in the fact that the or- dinary cloth or paper map becomes stretched out of proportion with folding and use, and scaling off such a map lends to notorious in- accuracies. The zinc top to the board was used in order to decrease map scale change. The essential targets were then plotted (after data had been obtained and plotted from the survey section as to the most essential landmarks), from the actual firing data after all corrections had been made for normal muzzle velocity, temperature of air and charge, wind direction and velocity, barometric varia- tion, and ammunition used. Line "xO" should also represent the line to a well-defined reference point. With the above indicated data and the addition, from time to time, of targets engaged, the artillery board becomes an accurate map which can be used night or day by the battery. The original points are accurately located by means of a transit or theodolite triangulation. Such accuracy is not attain- able, however, unless trench warfare is being employed. It is, moreover, unnecessary in moving warfare. In order that the above Qrti Here/ Board . 41 plan may work to the "best advantage, it becomes necessary that several triangulat ion points be available to the battery and the bearings from these to prominent points carefully marked so that, in case of accident, the points can be easily re-set. Artillery Register . An artillery register should con- sist of a tabulation of the essential results of battery surveys, and should be made out so that a similar battery might occupy the same position and be able to reproduce similar results without delay. It should consist of the original firing data, and also these data corrected for a gun of normal muzzle under normal con- ditions. Such a register is here indicated: Register of a Battery, Occupying Position with hone Aero Line Laid out on (here give map reference and describe) Signature of Commanding Officer The headings will be given in sequence and numbered consecutively. 1 2 3 4 " 5 6 7 8 9 10 11 12 13 14 15 1. Target Ho. 2. Apparent ’lap Range. 3. Deflection from v o " line. 4. Site. 5. Wind angle to B.T. line. 6. Wind velocity. 7. Charge Temperature. 8. Barometer pressure. 9. Air Temperature. 10. Correction for Type of Shell. 11. Apparent , d d O P O > 5 ^ o si d a> ttl) CQ r— I CO P CD p CO CO d ,d d o PP d O P o d P d g 'd d p d «H P P CD d P;P d • •* d CD CO d d d uQ POO o CD rH PL, CO P d P frfr 3 CD d 4-5 m C 4 05 d CO d r d d •» ra • • © 0 © tO H > •H jO O P J-t CO S P «H CO CO CD d rH «H t 3 'Ct CD 0) rd si p p «H P O O d u CD d ■d CD P P CD Pc d » d cd d a CQ •h si d *h p cjd >» d d CO CO P d d •H H 'o d CD p CO CD CO <1 d d d p d CD t> d d d p d o d P O & >* CD CD CQ P d Cb CD t> co d p CD o d o.si d d CD P d CM 3 d p ,-d & p d o 56 The gams are put into the pits from the front, and in case of enemy advance, can readily he run out to engage any kind of tar- get that might appear without necessarily demolishing the construc- tion. The pits also serve as rallying points for infantry, and can readily he considered as strong points for the operation of machine gun nests. During winter or trench operation, such pits protect the artillery personnel and insure better support to the infantry. This thesis has been ‘undertaken for two purposes, namely: First. , to show the gradual growth in the importance of artillery in modern warfare. Second , to endeavor to outline some of the problems of the artillery personnel and to record such experience as the writer has had which might he helpful in the future.