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    "source_key": "britannica_1926",
    "source_title": "Encyclopaedia Britannica (1926)",
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    "chunk_id": "1926:army:713c4343249c",
    "title": "ARMY",
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    "verified_text": "the following article constitutes an ac- count of the outstanding changes which have taken place since 19ro in the general principles governing the organisation and maintenance of armies. the first section of the article may be taken as applying to the military forces of all the great powers. there follow more particular discussions of the armies of the british empire and the united states. for details concerning the armies of the other great powers (france, germany, russia, italy, etc.), the reader should consult the articles on those countries. i. general as was only to be expected in view of the vast scale on which the world war was fought, of its protracted character, and of the impetus which was given during its progress to scientific investigation for military purposes, certain modifications were brought about during its course in the organisation of the armies that participated in the struggle. aviation.—one very important fresh factor had been brought into play even before hostilities commenced in aug. 1914, al- though it was then still almost in the embryo stage. this was the discovery between 1909 and rors that aviation was a prac- ticable undertaking, and the immediate recognition by soldiers that this new art could be turned to good account im the further- ance of military operations on land. the consequence was that {lying corps were introduced into several of the european armies between the years rg11 and 1913, and that, by the summer of 1914, each one of the major countries to become involved in the conflict could lay claim to possessing a number of efficient air units, fully equipped and ready to take the field. military au- thorities in general were, however, at that time disposed to take the view that the main purpose which aviators would be able to fulfil satisfactorily in face of the enemy was the carrying out of reconnaissance work, in some measure taking the place of cavalry in the performance of this important duty. but at a very early stage of the hostilities it became apparent that aeronautical units could and should fulfil other functions as well (see air warfare). the experience gained between 1914 and 1918 has caused all the more important european states, other than the united kingdom, italy and germany, to include in their armies aviation corps which are in all cases or- ganised on a considerably more ambitious scale than were the aviation corps which they possessed in r914. the united king- dom and italy have elected to divorce their flying corps entirely from their armies. germany is precluded by treaty from main- taining one, iveapons.—the most notable changes in this category are the increase in the proportion of machine guns and the number, calibre and mobility of heavy guns and howitzers; and the intro- duction of an entirely new weapon, namely the tank (q.2.). as regards machine guns, it should be mentioned that the germans took the field in r9r4 with a far larger proportion of army _ them than did any other belligerent. it was one cause of their early successes. their opponents speedily realised the impor- tance of the question, and they made desperate efforts to multi- ply their stock; this proved to be but a slow process, seeing that machine-guns take a particularly long time to manufacture. the lesson has, however, been learnt, and most armies to-day are adequately supplied with these weapons. although the germans were better fitted out at the outset of the struggle with mobile heavy howitzers than were the other belligerents, the full value of these and of mobile heavy guns in modern warfare only came to be recognised gradually even by them. the paramount importance that these forms of artillery ucquired on the western front as the conflict proceeded, was to some extent due to the form of sedentary trench warfare which the operations assumed after the first three months. but during the progress of the struggle in various theatres it became appar- ent that the “ caterpillar ’’ form of mechanical traction could be so developed as to make howitzers of great weight reasonably mobile and howitzers of medium weight highly mobile, and that such relatively ponderous forms of artillery were in consequence capable of being employed to good purpose even in campaigns of movement. the result of these experiences is to be seen in the numbers of batteries armed with such weapons maintained as an item in most armies of the present day (see artillery). tanks first appeared in the field in the summer of 1916 during the british offensive in the somme region, their manufacture and their presence with the troops having been kept a secret. their potentialities in trench warfare were recognised at once, but the united kingdom enjoyed a great advantage in having the start. the french immediately embarked on manufacture, aid the germans followed suit after capturing a few tanks. many improvements on the original pattern were devised before th: close of hostilities, and further improvements have been carried out since that date, with the result that tanks, which wete in the first instance introduced merely for the special pur- pose of attacking elaborate lines of trenches, are now capalle also of playing a prominent rele in the most mobile military operations. their design, morcover, is continuously undergoing elaboration and development. transport.—just as in civil life mechanical traction is tending to oust horse traction, so also in the military world lorries and the lighter forms of motor vehicle are more and more replacing the old horse-drawn wagons and carts and ambulances which used to trail behind the troops. but in the case of armies, the caterpillar type necessarily assumes a far greater importance than it does in civil life in countries that are provided with roads. although certain developments in respect of the employment of mechanical traction took place during the world war (quite apart from the question of tanks or of heavy artillery), the ten- dency of the day is to carry this considerably further. the idea is to make armies entirely independent of roads. cavalry.—the relative value of cavalry in normal conditions of warfare, as compared with that of the other two main arms— infantry and artillery—has been tending to decrease steadily, as the power of fire-arms in all forms has grown. the experiences of the world war have, on the whole, had the effect of thrusting mounted troops still more into the back-ground, partly owing to the development of aviation, and partly because cavalry can be of little assistance when trench warfare prevails. nevertheless, it was shown in palestine and also in mesopotamia that there was still plenty of scope for mounted troops and, even if most countries have been showing a disposition to reduce the strength of the mounted troops they maintain, the day of the mounted combatant is by no means over. in the course of the world war permanent troops, troops of the militia type and new formations all underwent exhaustive trial under varied circumstances, and each of the three cate- gories gave evidence of its worth under at least certain condi- tions. of regular troops nothing need be said. it has never been suggested even by the most enthusiastic believers in forces such as the british territorial army, that they come up to the high standard of efficiency expected of standing armies. 17 territorials and reserves—in regard to semi-permanent troops, it has to be acknowledged that the german reserve divisions, the french territorial divisions and the british ter- ritorial divisions, when first pitted against regular troops, were considerably below the standard of efficiency which they after- wards attained. they required time, coupled with a form of operations not calling for a high standard of training. and they were granted both. the first british territorial units to be placed in the field crossed the channel in sept. 1914; the last took the field some 17 months later; these troops were thus actu- ally fighting from 2? years to four years, and they were bound to learn their work before the war ended. the germans put most of their reserve divisions into the field at once, as did the french in the case of their territorial divisions, and neither german nor french non-permanent troops compared with per- manent troops during their early months in face of the enemy. new armies.—as regards troops only created at the outbreak of war, the british new armies set on foot by lord kitchener afforded a shining example in the world war. speaking gener- ally, these troops did well quite early, always provided that, after reaching the theatre of operations to which they were sent, they had been broken in to their duties by slow degrees. trench warfare generally admitted of this important principle being carried out. if tried severely at the start—as at the dardanelles —they were apt to fail. the first new army division crossed the channel to france in may 1915, nine months after the units composing it had been created; the last one took the field a year later. they performed magnificent service in all the later stages of the war; but they had all by that time met with ample oppor- tunities for learning their work, and nearly all of them, more- over, had spent many months in sedentary warfare before they were put to higher tests. opinion at british g.h.q. in france was at first disposed to ridicule the creation of these new armies. if that was partly because the magnitude of the struggle was not realised, nor its duration forseen, it was also a result of mis- taken notions as to the time required before newly created troops can be made fit to fight. it was generally assumed that a recruit must undergo several months of training before he was fit to be drafted to a regiment serving in the field, but experience in the later years of the war proved that a few weeks’ training is quite sufficient for drafting purposes. there were men in the corps which broke the hindenburg line at the end of sept. 1918 who four months before had not yet put uniform on. war wastage.—military ideas upon the subject of war wastage have perforce undergone a transformation since 1914 as a result of bitter experience. not one of the belligerent states taking part in the world war was prepared for the rate at which this wastage was to occur. it proved to be incomparably higher, than it had been in any previous contest, in spite of the fact that, thanks to improved medical arrangements and more efficient surgery, wastage from disease (except in unhealthy theatres like macedonia and east africa) was relatively small and the pro- portion of wounded men who speedily recovered was relatively very high. the premises upon which calculations as to strength of reserves required to keep a force of given strength in the field had been based proved to be valueless at a very early stage of the contest. the dardanelles campaign, for instance, lasted only 8{ months; but, although the maximum strength ofithe british army in the field was only 128,000, the casualties amounted to 112,000, including 39,000 killed or missing. an army to be properly organised for great operations of war must possess far greater reserves in some form or other than had been supposed to be necessary in the summer of 1914. chemical warfare-—chemical warfare played an important role in some of the theatres of operations during the world war, and is not unlikely to play a still more important one in wars of the future. but its introduction as an element in warfare is rather a question of tactics, equipment and research than of army organisation. the same holds good with respect to the employment of hand grenades, of trench mortars and other devices especially applicable to trench fighting (see chemical warfare). 218 il. the british empire the british army, in respect to organisation, stands very much where it did in 1914. its system of command and of ad- ministration has undergone little alteration. the system of recruiting, alike for the regular forces and for the territorial forces, remains practically as it was. its order of battle, suppos- ing it to be brought to a war footing, has only changed in points of detail. its powers of expansion in an emergency have been increased neither in principle nor in practice, in spite of all that has occurred since the year to11. at the beginning of aug. 1914 the military forces of the united kingdom, comprising the regu- lar army, the special reserve and the territorial force, were de- signed in case of a grave national emergency to place an expedi- tionary force of six divisions and a cavalry division in the field oversea, with an additional division to follow, and to retain 14 territorial divisions in the british isles for the purpose of home defence. the regular army also provided garrisons for a number of localities oversea. expansion tn 1914-5.-—no plan for the expansion of the british regular forces at home beyond the requirements of the expedi- tionary force, with its additional division, existed when the world war broke out, apart from the automatic embodiment of the special reserve, which provided units for home defence, and could be utilised for draft-producing purposes to replace wastage in the expeditionary force after the army reserve had been used up. lord kitchener, however, immecliately called home the bulk of the regulars from india and from the other oversea gar- risons, and by this means four further divisions were provided as an addition to the seven already contemplated. he, more- over, took immediate steps to duplicate the 14 territorial divi- sions and one of these newly improvised divisions, besides two of the old ones, had left england for india before the end of oct. to replace regulars brought home. but the greatest expansion of all took place in the form of the so-called “new army.” its first six divisions were created in sept., the next twelve were created in oct., the next six in nov. and the last six in jan. 1915. there was also a certain expansion of mounted troops, but not on alarge scale. actually, 55 divisions, recruited in the united kingdom, took part in the war, and there were also the three territorial divisions sent out to india in the autumn of rorq. when war was declared it had only been hoped to send abroad a force of 160,000 men, to be followed soon afterwards by another 20,000; but during the later stages of the contest the united kingdom had a field army of nearly a million and a half fighting in various theatres, besides the forces supplied by the dominions and colonies and india. in july ror4 the strength of the regulars, army reserve, spe- cial reserve and territorial forces was approximately 670,000; 4,970,000 men were recruited during the following 4} years within the united kingdom. recruiting remained voluntary up till march 1916, when compulsory service was introduced, in the first place for unmarried men, and subsequently for married men, between the ages of 18 and 41, unless exempted for medical or other special reasons. in the spring of 1918 an act was passed raising the age limit to 50 and cancelling various ee pre- viously in operation. dominions and colonies—at the beginning of the war the dominions and colonies had no more than some relatively small forces of permanent troops; they nevertheless placed large fighting forces in the field, the troops being in almost all cases freshly recruited and specially organised for the purpose. can- ada produced four divisions which took the field, besides another which was used for drafting purposes. australia produccd five divisions, and new zealand one. australia and new zealand, between them, also placed two divisions of mounted troops in the field. the troops raised in south africa were almost entirely employed in africa. table i. shows the numbers enlisted and scnt oversea. india.—the indian army at the outbreak of the war was organised in nine divisions, together with an incomplete division in burma. this organisation was, however, to some extent thrown out of gear by the recall of the greater part of the british army table i. total in dominion sent oversea arms canada 628,964 418,035 australia and tasmania 416,809 330,000 new zealand 220,699 100,471 south africa 136,070 74.196 | newfoundland 11,922 10,610 | troops to europe to fight on the western front; the territorial divisions sent out to replace these troops were not, at all events for the first few months, sufhciently trained to take the field, and they were to a large extent broken up and at first used for girrison purposes. india, nevertheless, contributed 10 divisions for work in field armies, besides finding the force which originally embarked on the campaign in east africa. of the divisions tha: took the field, only three were divisions that had existed before hostilities broke out; three more were organised during the early months of the contest. then, after the disasters in mesopo- tumia early in 19126, five entirely new divisions were created, of which four took the field before the end of the war, all of them proceeding to mesopotamia. of the divisions actually employed in various theatres, one was captured at kut and three were broken up during the conflict; so that at the time of the armi- stice there were actually only’ six in the field. the total number of natives of india enlisted during the progress of the war amounted to 1,524,087. the number of casualties suffered by the indian army during the course of the contest was approxi- mately 160,000, chiclly in mesopotamia, egypt and palestine the army since the war-—the reduction of the military forces recruited in the united kingdom to their peace footirg necessarily occupied considerable time; and even after the arri- stice they had to be kept more or less on war establishment for many months. not until 1921 could it be said that the army had got back to pre-war conditions, and its strength still greetly exceeded that of 1913, in spite of the air force having teen detached. the army estimates in 1922-3 amounted to £62,000,- 000, as compared with the figure {28,220,000 for the year 19:3-4. the geddes committee, however, took the matter in hand, and the equivalent of five cavalry regiments, 24 infantry battalions anda number of artillery units were reduced, saving £10,000,000. one important change carried out since the war has been the disappearance of the special reserve; there is, however, an inten- tion to restore the militia in course of time, and its battalions appear in the army list as skeletons. a supplementary reserve of ofliccrs and men was set on foot in 1924, the rank-and-file being mainly technical and arranged in two categories, trained and untrained. moreover, the territorial army is now asked to accept liability for service oversea in time of war, subject to sanction of parliament, instead of being intended purely for home defence as it was before 1914. the three branches of the royal artillery were re-amalgamated as regards officers in 1921, as a consequence of war experiences. two entirely new corps have been constituted—the royal corps of signallers and the royal tank corps. the former is an expansion of the arrange- ment under which signalling was mainly in the hands of the royal engineers, the latter a consequence of the introduction of the tank for war purposes in 1916. table it. shows the estab- lishments of the home forces provided for in army estimates in 1911 and 1926, and the establishments of the different branches of the regular army in those two years. the indian army since the war.—the demobilisation of the indian army was carried out more rapidly on the conclusion of hostilities after 1918 than was the case with the home troops, although the afghan war to some extent delayed the process. moreover, soon after demobilisation was complete, a reorgani- sation took place, the result of which was to reduce the strength of both the british and the native portions of the army to below the pre-war figure. some other changes of importance have also tuken place. in 1921, the forces as a whole were divided into four army commands—northern, eastern, southern and west- ern. in that year a territorial army was started, as also an indian army reserve of officers in two classes. the auxiliary forces were army table tu: category ioi 1926 regular forces . 168,233 142,432 army reserve e 138,000 96,000 special keserve . , ‘ : : 86,539 te supplementary reserve . ‘ : id 23.751 militia reserve . : : ? 790 ~ militia channel islands. ; 4.363 1,325 malta and bermuda militia 2,894 tha? territorial forces 315,403! 186,093 officers’ training corps $23 to45 total 715,760. 451,633 branch init 1926 cavalry 14,562 9,630 artillery f : 32,881 211233 engineers. : ; : : 9,610 6,623 corps of signallers. ‘ : se 5,013 infantry : ; 96,182 77,457 tank corps : 23 3,294 asigy = 6,696 1303 raudic:. : ; , yd 4,637 4,163 other departmental corps and ' establishments : ; 3,465 5,666 1267,500 effective also reorganised and rendered more efficient. it was decided that the field army should consist of four divisions and five cavalry brigades. the following table shows the numbers of combatant british regular units maintained in india in the years torr and 1926 respectively :— british: cavalry regiments iatteries . infantry battalions the establishments of various units making up the british military forces in india in 1926 made an approximate total of 61,550. bisliograppity.—a. perein, la guerre et l'armee de demain (1917); baron h. f. p. j. von freytag-loringhoven, geschitites volksheer oder aftliz (1918), translated into fenglish, with introduction by sir c. e. callwall (1918); lord moulton, science and war (1919); oir i, s. m. hamilton, the soul and body of an army (1921); ey ludendorff, ariegfithrung und politik (1922). (cu bae) if. the united states on feb. 27 1911 congress added 200 line officers to the regu- lar army in order to mect the demands of the national guard for instructors; increased the corps of engineers by 60 officers; gave 60 dental surgeons to the service, and rectified relative rank for those adversely affected by regimental promotion. on aug. 24 1912 an act, commonly known as the ‘‘ manchu law,” required line officers to serve two years out of every six with troops. on april 27 1914 congress gave $250,000 for aircraft, and on july 18 1914 it authorised an aviation section of the sig- nal corps, totalling 60 officers and 260 enlisted men. on june 3 1916 came the national defence act, which in- creased the regular army from a war maximum of 128,653 to one of 287,846; organised the army of the united states into the regular army, volunteer army, officers reserve corps, enlisted reserve corps and the national guard while in the service of the united states; provided for the aforesaid increase in five annual increments, unless the president desired in an emergency to call out the whole force; limited the number of enlisted men of the line to 175,000; proportioned the regular army into 65 regiments of infantry, 25 of cavalry, 21 of field artillery, seven of engineers, a coast artillery corps, two battalions of mounted engineers and other corps, and bureaux of the war dept.; established the or- ganisation of a division into three brigades of three regiments each, with auxiliary troops; made the term of enlistment seven years, three with the colours and four with the reserve; inaugu- rated vocational training and federalised the national guard by causing each member thereof to take a new oath, which bound 219 him to the will of the president as well as to state authority. on aug. 29 1916 another act created a council of national defence, composed of the secretaries of war, the navy, the in- terior, agriculture, commerce and labour, for the “ co-ordina- tion of industries and resources for the national security and welfare.” mexico —on march 9 1916 the mexican bandit, pancho villa, with about 1,500 men, having attacked columbus, n.m., and having killed 18 americans and wounded many others, units of the regular army and national guard were concentrated along the border, and brig.-gen. j. j. pershing was sent into mexico at the head of a provisional division of regulars (two brigades of cavalry and one of infantry with auxiliary troops). after about 12 minor engagements the expedition was called home and the national guard organisations were ordered to their respective states (i’eb. 1917). for the great conflict about to ensue this mexican campaign gave extra training to the na- tional guard and demonstrated to the war dept. a deficiency in means of transportation for all troops. the world war.—on april 6 19017, when the united states came into the world war, the regular army had received only its first increment from the act of 1916, and the national guard was undergoing combined demobilisation and reorganisation. the strength of the united states forces on april 1 1917 was 199,705 officers and enlisted men, of whom 127,588 were regular army, 5,523 philippine scouts and 66,3904 national guard in the federal service. in addition, there were some 4,000 in the en- listed reserve corps and some 117,500 national guardsmen not 11 the federal service. the regular army was distributed as follows: united states (especially on the mexican frontier), 83,708; philippines, 17,951; china, 1,383; hawaii, 9,c00; pan- ama canal zone, 7,300; porto rico, 1,484; alaska, 772. as to o:licers, there were 5,960 in the regular army, some 3,000 in the oficers’ reserve corps and 3,199 national guardsmen in the fed- eral service, making a total of over 12,000. in addition, there were some 5,000 national guard officers in state service. mobilisation—the three great problems which confronted the general staff in obtaining a proper army were: first, the lack of any legalised system for raising a sufficient number of men in an equitable and efficient way; second, the great dearth of officers as instructors and trainers; and third, the immediate demand for sufficient shelter and supplies for the large numbers of men necessary for the work in hand. the first problem was met by the selective service act, may 18 1917, which in substance brought the regular army to full war strength and provided for drafting all members of the na- tional guard and its reserves, for raising by voluntary enlist- ment only four infantry divisions, and for conscripting a force of 1,000,000 men. as a result, on june § 1917, there registered for the draft 9,925,751 men; and on july 3 1917 the president called into service the entire national guard, with a resulting total of 379,323 by aug. § 1917. the calling of the first draft to the colours was delayed by lack of shelter and supplies, especially woollen clothing, until sept. 5 1917, between which time and the spring of 1918 some 687,000 reported. on dec. 15 1917 all reg- istrants were placed in five classes, according to personal condi- tions and national needs. out of some 3,700,000 men in the army at the end of the war, about 2,800,000 came from the draft, which had made possible a uniform supply of recruits and replacements for american arms. the second problem was met principally by three sets of re- serve officers’ training camps. the first series of 16 camps, be- ginning may 15 1917 at 13 army posts in the united states, enrolled approximately 38,000 qualified applicants. on aug. ir 1917, at the conclusion of the course, commissions in various grades up to colonel were awarded 27,341 graduates. the second series of eight camps, beginning aug. 27 10917, enrolled over 20,000 candidates. on nov. 27 1917 commissions as in the first series were awarded to 17,237 graduates. ‘these two series were composed largely of college men. since no coloured candidates had been admitted to these camps, a special school for them at fort des moines, ia., beginning june 18 1917 and ending oct. 220 (8 1917, graduated 639 captains and licutenants. in porto rico three camps, covering the period from aug. 27 1917 to nov. 6 1918, graduated 711 captains and lieutenants. the third series of 27 training camps, beginning jan. 5 1918, were more in the nature of schools; and 90% of the applicants were former enlisted men. from this series, on april 19 1918, three were graduated and listed as eligible for appointment as second lieutenants 11,659 men. at this time, the total output of the camps was over 57,000 graduates. after may 15 1918 officers’ training schools, established throughout the united states and its possessions, replaced the camps until the end of the war. the supply question.—the third problem was not so speedily solved, principally because of the lack of preparation for under- takings of such kind and magnitude. it was necessary at once to mobilise resources and industry, to organise adequate trans- portation, to obtain storage, distribution, and ports in the united states and france and to construct cantonments for training the vast numbers of recruits soon to come. the council of na- tional defence by its sub-committees and dollar-a-year men! gained immediate contact with commerce and industry and was the father of the powerful war industries board, created for- mally on march 4 1918, with mr. bernard m. baruch as its chair- man. the new board co-ordinated and controlled resources, in- dustry and transportation so as to produce an adequate flow of supply to the army and navy, without impeding unnecessa- rily commercial activity in the united states. operating within the army, much as the board was acting for the country, were the operations and the purchase, storage and traffic divisions of the general staff. by an interlocking organisation of these various co-operating agencies, tedious, duplicating and extravagant systems of supply were gradually eliminated. the flow of materials through the united states to the western front is shown by the fact that by the date of the armistice the embarkation service had sent about 9,000,000 tons of cargo over a line of communication 3,500 m. long. within a few weeks after the inauguration of the system of control made by the inland traftic service, the freight congestion in the united states was removed, and from may 1917 to the armistice the railways had transported 8,714,582 men. shortly after war was declared the construction diviston was called upon to build in 90 days 16 national army canton- ments with an aggregate capacity of 640,000 men. in addition, housing for 16 officers’ training camps and for 16 national guard cantonments had to be expeditiously procured. by nov. 1 1918 the construction division, with 130,000 employces, was engaged on 448 projects involving $756,000,000. american expeditionary forces —on may 26 1917 the secre- tary of war, in a letter to maj.-gen. j. j. pershing, directed him to command the land forces of the united states operating in continental europe; to proceed there with his statf and establish, after consultation with the french war office, bases, lines of communication and depets for active participation at the front; to co-operate with the troops of the other countries employed against the enemy and in so doing to preserve the identity of the forces of the united states. pershing sailed immediately with a small staff, and one month after the date of the above letter maj.-gen. sibert, with the 16th, 18th, 26th and 28th infantry of the regular army and the sth marines, arrived in france as the first contingent of persh- ing’s command. the next to begin to arrive was the 2nd div. in aug. 1917, and by march 1918 four complete combat divi- sions, the rst, 2nd, 26th and 42nd, were in europe. pershing’s ‘ organisation project of july 10 1917” contemplated a ship- ment overseas during 1917 and 1918 of 30 divisions. by july 1918, under his ‘‘ schedule of priority shipments, ” there were transported g96,000 men. a subsequent programme of gen. p. c. march, chief of staff, july 18 1918, proposed the landing of 80 divisions by the middle of rg19, or a force of 3,360,000. under the latter scheme, by aug. 1918 the number sent over- 1 people who carried out public duties for a purely nominal remu- neration. army seas increased to 1,576,000, and by the time of the armistice rose to 2,085,000, or to 41 american divisions and a part of another. . the ist div. entered the trenches for instruction on oct. 20 1917, and took over a division sector on jan. 19 1918, north of toul. on march 28 1918 pershing placed all the american forces, four trained and two untrained divisions,? at the disposal of the allied commander-in-chief. on may 28 10918 the rst div., fighting as a unit, made a successful attack on cantigny; at the same time 16 american divisions (six trained) were placed at the disposal of the alles. during july 15-18 the 3rd, 28th, 42nd and parts of the 92nd divs. aided in the defeat of the last german offensive on the champagne-marne front. | meanwhile, the organisations of divisions into higher units was proceeding with difficulty. although the 1., it., wy. and iv. corps headquarters were organised between jan. and june, it was not until july 4 that the i. corps, consisting of the 26th american and 167th french divs., was assigned a tactical com- mand at the point of the marne salient west of chateau-thierry. from july 18 to aug. 6 the ist, 2nd, 3rd, 4th, 26th, 28th, 32nd and 42nd divs. (mainly comprehended in the j. and iti. corps) formed 30% of the allied strength in the aisne-marne offensive. the american i. army, under the command of gen. pershing, was organised in the chateau-thierry region and began to func- tion on aug. 10, but upon stabilisation of the aisne-marne offen- sive along the vesle river shifted its operations eastward. from sept. 12-16 the i. army, containing the i., iv. and v. corps with a total of 11 american and four french divisions, reduced the st. mihiel salient. this army, beginning its attack on sept. 26 in the mcuse-argonne operation with the iii, v. and i. corps, employed in this offensive 25 american divisions and one french cavalry division. by oct. 12 the american ii. army had completed its organisation, and with the iv. and vi. corps went into line generally west of the moselle. in addition to these operations two american divisions served with the british on the ypres-lys and three in the somme offensive; three participated with the french in the oise-aisne operation, two with the french iv. army in champagne, and two with the french and the belgians in flanders. by the date of the armis- tice, 29 american divisions had been engaged in active fighting and american forces were holding 134 km. or 22% of the entire western front, having captured some 63,000 prisoners, 1,378 cannon and 9,650 machine-guns. ‘their casualties were: killed in action, 36,780; died of wounds, 13,466; died of disease and other causes, 27,293; total overseas dead, 77,539; total wounded, 234,852; prisoners, 4,416. the supply of the american expeditionary forces was handled in france by the line of communications, which in feb. 1918 was changed to the services of supply or 8.0.8. this vast organ- isation in rear of the combat zone was charged with immense projects involving roads, docks, railways and buildings; the transportation of men, animals and munitions by sea, rail and inland waterways; the operation of telephone and telegraph systems; the control of replacements; the hospitalisation neces- sary for an army of 2,000,c00 men; the reclassification of officers and men; the establishment of leave areas and of welfare and entertainment projects; the liquidation of american affairs in france; and the embarkation of troops for home. in addition to the materials serit from the united states, these services pur- chased 10,000,000 tons abroad; the communication system cov- ered 215,500 km. of telephone and telegraph lines; the engincers produced 200,000,000 feet of lumber; the transportation corps put 26,000 american cars and 1,500 american locomotives on french railways; and the medical units on nov. 12 1918 were caring for 193,026 patients in hospitals. by the time of the armistice the strength of the s.o.s. was 668,312 men. other fronts —ain sept. 1918 an expeditionary force of some 10,000 men was sent to siberia. at other times some 5,000 men went to north russia and one regiment served in italy. demobilisation—the armistice necessitated the demobilisa- 2 an american division was practically twice the size of a british, french or german division. arras, ba't'tle of tion of some 3,700,000 in service oversea and in the united states, the termination of contracts with due regard to the in- terests of industry and the government, the co-ordination with labour over the employment situation and the prevention of congestion of ex-soldiers in the larger cities. on the morning of nov. 11 1918 gen. march issued orders for the immediate discontinuance of all mobilisation; on nov. 16 he gave specific instructions for the discharge of certain tem- porary forces in the united states; on nov. 22 he issued instruc- tions to pershing covering procedure which would facilitate <lis- charge in the united states of the oversea forces, but left to the commander-in-chief of the american expeditionary forces the order of return of units. the demobilisation of personnel in- volved intricate problems of the care and habilitation of sick and wounded, the location of demobilisation camps, the discharge of special classes for relief of distress and the needs of industry, the avoidance of congestion of labour, the economy to, be exercised in transporting discharged soldiers and the procedure at demo- bilisation camps involving physical examinations and disinfec- tion of discharged soldiers. it was necessary to retain in the service, in addition to the regular army, a large number who were indispensable to the care of billions of dollars’ worth of property, and to the work connected with debarkation, demobilisation and convalescent centres, hospitals, domestic guard duty, fire protection and border police. by jan. 4 1919 there were discharged 732,766 men; by feb. 1 the number had increased to 1,026,664; by may 1, to 1,936,011; and by july 1, to 2,736,654. by april 1 1920 demobilisation of enlisted men was practically completed. in addition to the demobilisation of personnel, the army was called upon to cause industry to return speedily to its peacetime course, after labour, capital and manufacture had been occupied for a year and a half in preparing materials for war. the problems confronting the war dept. during the transition included the disposal of war supplies, the appropriate rate of curtailment of war production so as not to create widespread unemployment and economic disturbance, the settlement of claims and contracts, the adjustment of real estate connected with war activities, the liquidation of international obligations and of sales abroad. on nov. 11 1918 the equipment branch of the operations division, general staff, made a study of existing supplies, which resulted in the classification of materials and the retention of a war reserve. during jan. ro1g there was established a claims board, which by the middle of the year had adjusted 25,196 con- ‘tracts, besides those allowed to run. by sept. 1 1919 property in the united states costing bee $700,000,000 had been sold for about $530,000,000 or 77% of its cost. surplus property in france estimated to have ou $1,250,000,000 was sold for about $s00,000,0c00. out of an estimated value of $3,276,340,533 worth of surplus property on hand at the armistice, there te- mained in jan. 1926 only $9,278,269 worth, the materials repre- sented by the dilference having been sold at an average of 36°% of their cost. phases since the war—lin order to overcome the waste and confusion incident to unpreparedness, congress passed on june 4 1920 the national defence act, which established the army of the united states in the approximate proportions of one-half organised reserves, one-third national guard when called into service, and one-sixth regular army, the last factor being limited to 280,000 officers and men. for training and tactical control, the country and its possessions were divided into corps areas, all three components of the army within each area being potentially organised for prompt mobilisation. the regular army, the com- ponent engaged primarily in military training, was to be respon- sible for the instruction and proficiency of the other two compo- nents. the president could change the strength of the different arms to suit varying demands of national defence and the developments of the new services, such as air, chemical warfare and tank corps. within the regular army a single promotion list for officers throughout all branches, except the medical corps, equalised advancement by seniority. provision was made for reserve officers’ training corps in colleges and for training camps 22k during summer months. altogether, the legislation was viewed generally as the first sound military policy of the united states. accordingly, in 1921, the army spent its efforts upon training and recruiting qualified personnel. on june 30 1922 congress reduced the regular army to a maximum of 175,000 officers and men, and later in the year made the maximum for officers 12,000, so that it was necessary to separate from the service over 100,000 officers and men, many of whom had recently enlisted or been commissioned. by dec. 1 1925 the strength of the army of the united states was: organised reserves, 98,585 officers and 5,600 enlisted men; national guard, 11,673 officers and 166,080 enlisted men; regular army, 11,957 officers and 124,249 enlisted men, 38,714 of the regular force being stationed abroad. see the war with germany: a statis- tical summury (u.s.a. war office, 1919). (d. d.) arras, battle of.—the great battles which opened the campaign of the allies in 1917 on the western front were the direct outcome of two main causes, the first was the strategical position resulting from the battle of the aisne in ro14, and the sccond the tactical position resulting from the battle of the somme in 1916. the former placed the bulk of the german forces in the west in the huge salient nieuport-noyon-verdun, and the second ee, arleux- en-gohelle zo oppy ecurie roclincourt blang a zs. ay oa ‘mz “x % . 4 st.la ' a es a gy?) ee 'monchy-o,f fp pes y rags j bits | f feuchy shape -vitas , + neuville \\ sn henin ay sur cojeul® y, arras english miles 1 kilometres oo j 2 main roads other 2: main railways frent tine aprit 9th. 1917 qmmamemn fst. oyeeive (black hine} a on oe 2nd. {sise >) se = (growl x )} eam ames (creen us) avenue a considerable portion of these forces in the smaller salient arras-gommecourt-morval. the first offered considerable pos- sibilities for the allies to get in a right and ieft hand blow on valenciennes and meezicres, the main centres of the german lat- eral communications, and the second of similar blows in the direc- tion of queant against the northern and southern flanks of the german vi. and i. armies. if it had been possible to bring off this last operation successfully, such a debacle of the german forces would have resulted that not only would the advance of the brit- ish armies scriously threaten valenciennes, but the rush of 222 german reserves to stop the gap would have withdrawn pressure from before the french about reims, and would probably have enabled them to advance on mezieres. alternative plans.—in june 1916 a plan, known as the blaire- ville project, was prepared, the object of which was to strike at the germans between monchy-au-bois and beaurains during the later stages of the battle of the somme, but on account of the casualties sustained during the early stages of this battle, this project was abandoned. in oct. the project was revived and its scope extended. a simultaneous offensive on all fronts was suggested, in which, whilst the main attack was to be made by the british, a subsidiary attack was to be carried out by the french in the neighbourhood of reims. in oct. the british plan included the following operations. at the earliest date pos- sible (about march 15 to917) the iv. and v. armies were to re- assume the offensive and the iii. to strike between beaurains and arras, occupy monchy-le-preux, and by pushing southeast, deny to the germans the cojeul valley as a line of retreat, and, if possible, that of the sensee also. meanwhile the j. army was to attack north of the scarpe and form a defensive flank. in dec. gen. nivelle, who had recently been appointed to the chief command of the french armies, objected to the subsidiary part to be played by the french, and put forward a plan in which the decisive blow was to be delivered from the aisne. the task of the british, according to this plan, was to deliver an offensive in artois which would draw in large forces of the enemy, and so reduce opposition on the french front. further, to assist in the french concentration, as a preliminary measure, gen. nivelle insisted that the british should relieve the french forces as far south as the amiens-roye road, and that this relief should be completed by march 1, the offensive to open on april 1. from oct. onwards vast preparations, which were impossible to disguise, were put in hand. railways and roads were extend- ed, dumps formed, gun emplacements built, aerodromes levelled and the greater portion of the underground quarries of arras, st. sauveur and ronville opened up and made ready in every detail to accommodate two divisions which' were to reinforce the attack by passing underground. this sudden and unexpected reinforcing of the front was to be the surprise of the battle. preliminartes.—meanwhile a hostile operation was begun which bid fair to filch from the british the tactical advantage won during the preceding summer. towards the end of ieb. it became apparent that the germans intended to evacuate the gommecourt salient, and the recent construction of the hindenburg line suggested a rounding off of the right angle be- tween arras and craonne. if this could be successfully accom- plished, not only could the tactical blow against the gomme- court salient be avoided, but the strategical blows against valen- ciennes and mezieres be impeded or delayed. the problem which now faced the allies was a threefold one, namely, whether to hit at once, or recast their plan, or finish their preparations and carry it out as originally intended. as weather impeded the first and want of time the second, the third was adopted with the following modifications. the iii. army was now to play the leading part, and by attacking north and south of the river scarpe with three corps, whilst holding one corps and the cavalry corps in reserve, was to penetrate the german defences and by advancing on cambrai turn the hindenburg line from heninel and marcoing. the i. and ¥. armies were to operate on the left and right flanks of the iii. army. the battle front, some 1g5 m. in width, extended from just north of croisilles to a little south of givenchy-en-gohelle, at the northern foot of the vimy ridge. this ridge which rises to a height of 475 ft. above sea level dominated the whole battlefield from the north. from its summit overlooking lens the ground falls away to the river scarpe, between which and the cojeul river it is in nature undulating. in the forward zone of defence the germans had dug three lines of trenches, each of which was heavily wired. then four to five miles east of this system was dug the drocourt-queant line, which at the date of the battle was still unfinished and but lightly wired. arras, battle of at the beginning of april the german reserves numbered some 600,000 men, and consequently the success of the battle depended on the time it would take to penetrate the drocourt- queant line. if this line could be broken within 48 hours of the initial attack, the intervention of these reserves might be avoided and so large a gap created that eventually great numbers would be drawn towards it and away from the french offensive in the south, where the main blow was to fall. this time could only have been gained by the employment of a considerable number of tanks, or by a preliminary bombardment of not more than 24 hours duration. after denuding the training grounds of both france and england, only 60 tanks could be assembled, therefore the only alternative was a hurricane bombardment, and though the iii. army for long suggested such an operation, g.h.q. in- sisted on three weeks systematic wire cutting culminating in a general bombardment of several days’ duration. during this period 2,700,000 shells were fired, and though the wire was de- stroyed all chance of surprise vanished. plan of attack.—the final plan of attack was as follows:— (a) itt. army (gen. sir e. h. h. allenby). the vi. and vii. corps were to attack south of the scarpe between arras and mer- catel. their objective ran from a point 2,000 yd. southeast of henin sur cojeul northwards to guemappe, thence east of monchy-le- preux to the scarpe. this objective contained two formidable lines of defence, namely, the cojeul-neuville vitasse-telegraph iiill- tilloy-lez-motiaines line, and the feuchy chapel-feuchy line. south of these were some 3,000 yd. of the hindenburg line, and east the strong position of monchy-le-preux which dominates the whole of the surrounding country. the xvii. corps was to continue the front of attack north of the scarpe. (6) fe. army (gen. sir eh. s. horne). the canadian corps and the 13th bde. of the 5th british div. were to attack the vimy heights, vhelus and the hill north of thelus, a position considered one of the strongest in france. (c) v. army (gen. sir h. gough). the australian corps and the v. corps were to operate between lagnicourt and the right of the ii. army northwards towards vis-en-artois. the position of this army was a most difficult one, as the destruction of the roads and the bad weather had rendered it impossible to move forward much artillery, a sine qua non of the battles of this period. (¢) the whole of the above operations was to be considered as a preliminary step to the advance of the cavalry corps and the xviii. corps south of the scarpe. these corps were to break through at monchy-le-preux and advance eastwards through the drocourt-queant line. opening of the attack—on april 9, at 5.30 a.m., the general attack was launched under cover of a magnificently timed creeping barrage, and within 40 minutes the whole of the ger- man first line system, except a small portion of the vimy ridge, was captured. about tilloy-lez-mafflaines and telegraph hill tanks accounted for a good many of the enemy and then pro- ceeded eastwards to assist in the reduction of the blue line and such parts of the brown line as they were able to reach during daylight. by noon the greater part of the second objective had fallen and a number of hostile batteries were captured. by the close of the day practically the whole of the objectives north of the scarpe had been taken, but south of this river the third objective had only been penetrated in places, and the fourth objective remained untouched. during the night of the gth-1oth, the 37th div., which had been held in reserve, advanced to the northern slopes of orange hill; and during the morning of the roth this advance was followed by a general attack on the brown line which enabled the 37th div. to reach the outskirts of monchy-le-preux, which on the morning of the r1th was captured by this division assisted by tanks. whilst these operations were in progress the germans strongly reinforced their front, and so stubborn had become the opposition that to relieve the pressure on the vii. and vi. corps fronts the v. army was ordered to attack on the morning of the 1rth from the direction of bullecourt northwards. at 4.30 a.m. 11 tanks, followed by the 62nd div. on the left and the 4th australian div. on the right, stormed the hindenburg line, but on account of the width of the trenches and inadequate artillery support only two tanks, co-operating with the australians, were able to cross this line. these led the attack as far as riencourt- lez-cagnicourt when a strong german counter-attack drove the australians back; meanwhile the attack of the 62nd div. had arrhenius—artipficial silk been completely held up on the southern outskirts of the village of bullecourt. on the 12th, heninel and wancourt were captured by the 21st and 56th div., and minor operations were carried out on the 13th and 14th when the main offensive of the iii. and v. armics terminated, 13,000 prisoners and 2co guns having been captured. pressure, however, was not altogether relaxed, as on the 16th the french launched their grand offensive on the aisne, and to assist in this operation it was considered necessary to hold the enemy. though this attack proved a complete fiasco, pressure was maintained on the arras front, and the hine pushed for- ward to include the villages of guemappe, gavrelle and arleux- en-gohelle. on may 5 the battle of arras was brought to a close. since april 14 6,000 additional prisoners and some 50 guns were taken, but british casualties had been severe, totalling, between april 9 and may 5, no less than 132,000 officers and men killed, wounded and missing. results of the battle —the failure of the allied spring offensive may be traced to various causes, the most important being: the exhaustion of the french due to the battles of verdun and the somme in 1916, the total lack of surprise on both the british and french fronts; the distance apart of the two battlefields, and the comparative narrowness of the fronts attacked when compared with the strength of the german reserves. the results of this failure and their influence on future operations were clearly brought out by sir douglas haig at a conference of army commanders held at noyelle-vion on april 30. on this occasion he said:— as regards the french, their losses had been heavy and they could not continue to operate by similar methods to those which they had employed since their main offensive launched on the 16th april. there was a possibility of changes in the french higher command. this contingency would doubtless alter the military policy of the french, which would then probably be of a defensive nature with a tendency to avoid losses. although the french war minister and prime minister had given an assurance that offensive operations would be carried on, it was doubtful whether it was possible for the french army to prosecute these on a large scale . . . he continued that it was his intention to move steadily forward up to a good de- fensive line. . . . once this line has been reached it will be possible to decide further action. it may then be necessary to continue on our present front, to attack on the havrincourt front, or to shift the centre of gravity up to the second army. [n the meantime it is necessary to hold the enemy and make him think that we are undertaking a methadical offensive similar to our operations last year on the somme. bibliography.—j. f. c. fuller, tanks in the great war (1920); h. steele, the canadians tn france 1915-1918 (1920); j. shakespear, thirty-fourth diviston 1915-rotg (1921); j. buchan, a jiistery of the great war, 4 vol. (1922). see also world war: bibliography. ce fegi fe) arrhenius, svante august (1859- ) swedish chem- ist (see 2.648), was born at wijk, near uppsala, sweden, on feb. 19 1859. he was educated at the cathedral school and the university of uppsala. in 1895 he was appointed professor of physics in the university of stockholm, and in 1905 became direc- tor of the physico-chemical department of the nobel institute. he devoted himself especially to the study of electrolysis and evolved the theory of electrolytic dissociation. in 1903 he was awarded the nobel prize for chemistry, and received, among numerous other foreign distinctions, the davy and faraday medals of the royal society. among his works are immunochemistry (1907); theories of chem- istry (1907); worlds in the making (1908); quantitative laws in biologi- cal chemistry (1915), all written in swedish and translated. arriaga brun da silveira e peyrelongue, manoel jose d’ (1839-1917), portuguese politician, was born in horta, in the azores, july 8 1839. educated at the university of coimbra, he graduated in law in 1866. arriaga early showed signs of his republican sympathies, with the result that his father, an ardent royalist, disinherited him; and as a student he was obliged to support himself by coaching his juniors. he had a distinguished scholastic career, among his appointments being the rectorship of the university of coimbra and a professorship at the lyceum in lisbon. his political career opened in 1882, when he was elected republican deputy for funchal. from 1890 223 to 1892 he represented lisbon. during the revolution of 1910 (see portugal) he was a prominent figure on the republican side; and on aug. 24 1911 he was elected first constitutional president of the portuguese republic. the royalist risings of igtr and 1912 taxed the strength of the president; and in 1915, feeling no longer able to cope with the difficulties of the situation particularly in face of the coup d'etat of may 14, he resigned on may 27. arriaga died march 5 1917. art: see aesthetics; decorative art} painting, etc. artificial silk, or rayon.—any plastic form of cellulose or derivative can be extended or drawn in continuous length. the plastic form is conditioned by associated solvents, which, in the case of fluid solutions, are in multiple proportion by weight of the cellulose or derivative. the drawing to thread, filament or film can be taken to a limit of attenuation dependent upon the structural qualities of the colloidal matter present in its 7 to 12% solution. the silkworm elaborates, from its vegetable diet, a nitrogenous, colloidal complex, very different from cellulose in constitution and properties, in the form of a hydrated, plastic mass, which it spins, or rather draws to a thread; the thread is laid into the symmetrical form of cocoon, incidentally passing, by chemical changes of internal and external reaction, to insoluble forms. thus the insect labours, and man enters into the fruit of its labours, largely forgetful of the wonderful worm. the artificial silk industry owes its obvious debt to the worm, and is prevented from forgetting it by the difficulty of coining an autobasic de- scriptive term. if in the course of this article we use the alterna- tive “ lustra cellulose,” it is only as an expedient. rise of the industry.—industrial artificial silk is a wonder even of the zoth century. its development may be briefly set out un- der the dates of the various stages:— _ 1883. hilaire de chardonnet described the invention of produc- ing thread by drawing solution of nitrocellulose through fine orifices. 1890-1900, the industrial process including regeneration of cellulose from ihe nitrate thread perfected. formation of the societe d’exploitation ‘“ soie artificiclle chardonnet \"’ and produc- tion of artificial silk at besancon. 1892. cross and bevan patented the viscose process of dissolving cellulose, and 1895. formed the viscose spinning syndicate and applied the process to the production of thread in association with c. h. stearn and c. topham. the latter invented the centrifugal spinning box and process in substitution of the method of parallel drawing, and afterwards twisting the fibres to the textile compound thread. _ 1900-1902. societe frangaise de la viscose was formed and reached industrial production of viscose silk at arques la bataiile. _ 1902-1907. british-american developments organised by s. courtauld & co. (h. g. tetley & t. latham). in these earlier stages a third process played a leading part in competition with the chardonnet. this was the cuprammonium process of dissolving the cellulose and drawing it to thread by coagulation to hydrated colloid in either acid or alkaline medium. this was based on the pioneer labours of pauly, fremery, urbain and bronnert, and the silk known as glanzstoff consti- tuted a considerable proportion of the 8,000 to 9,000 tons which was the average annual production of the new textile material in the period 1910-2. to complete the story of increase and ever- widening production, and of the survival under competition of the three systems, we give the aggregate figures for the several producing countries of 1924. estimate of production of artificial suk, 1924 metric metric tons tons united states . 16,245 austria 1,200 england 10,885 poland 700 germany . 10,760 czechoslovakia 588 ltaly . 8,400 japan. 545 france 5,606 hlungary : 280 belgium 4,034 spain : 2 84 switzerland 1,820 sweden . : : 80 holland 1,530 russia. : : 40 this amount of 62,797 tons was produced by 79 firms, op- erating 95 factories, and includes 4,900 tons of chardonnet silk, goo tons of cuprammonium silk and 54,197 tons of viscose silk. these figures are compiled from the statistical records of court- 224 aulds, ltd. the output of the three cellulose silks mentioned above is less than the aggregate of the preceding table by 2,800 tons. this is attributable to the introduction of cclanese, which is produced mainly by the british company of that name. the antecedent british cellulose co. with works at spondon, derby- shire, undertook the manufacture of the acetate in great britain as the colloidal basis of the varnish or dope applied to aeroplane wings. as a war service the enterprise was in part financed by the british government. in the last year of the world war the production of the dope reached the figure of 5,000,000 gal., which at r ib. of acetate per gal. would account for the production of 8 tons a day at spondon. at the conclusion of the war the demand for the dope fell to fractional proportions, and the technical staff of the company developed commercially the potentialities of the acetate in the production of silk thread, non- inflammable photographic film, and solid celluloid substitute. as for the uses to which the material is put it has been esti- mated that, as regards the united states, which is the largest market for it in the world, 28% is made into hosiery, 26% is mixcd with cotton and 16% with silk. about 13° is used in the manufacture of underwear and the balance is put to a variety of uses, which are increasing almost every day. the potentialities of the yarn appear therefore to be tremendous both in the old and the new world. processes.—in considering various qualifying factors we have to revert to the process itself, and to the technical principles involved in drawing the solution of cellulose to thread. ‘the unit thread is coarse or fine in terms of its diameter; in exact terms it is the ratio of weight to length. in the silk counts the unit is the denier. for the present purpose the denier is the metric denier of 1 milligram per 10 metres; natural silk is a thread of 1 to 2 deniers. artificial silk, in the early years of pro- duction, was a unit of 6 to 7 deniers, but it was evident to the inventors that finer dimensions were attainable; in the case of the anhydro ester silks by merely reducing the diameter of the ‘‘ spinning ” orifice, and in the case of aqueous solutions, by “drawing down ” the thread in the fixing bath. this process of stretch drawing is a refinement of the earlier processes of direct ‘‘ spinning,” in which the thread of cellulose-hydrate (cellulose 17%, hydration water 83%) is formed in the first few cm. of contact of the cellulose solution with the fixing solution of the setting bath. it has been especially developed under the thiele patents and in connection with the cuprammonium solu- tion of cellulose. the present industrial specialisation in yarns. of fine counts is that of the brysilka co. (apperley bridge, york- shire), and of certain firms on the continent of europe. the process involves drawing under vacuum through a column of fixing solution contained in a funnel, and exact control of all the auxiliary conditions. the viscose reactions of decomposition with ultimate regenera- tion of cellulose (hydrate) are by contrast intrinsic and accom- panied by interior effects of reaggregation; there are therefore a number of “ fixing” reagenis which condition a graduated action of the “ setting’ bath, which allows the drawing tension on the thread to take effect in attenuation. viscose threads of 1 to 3 deniers can therefore be “spun” by the direct process and by various of the more obvious alternatives. but on the trend of the market during 1924 toward yarns of the heavier deniers, the viscose companies have not found it advantageous to compete with their rivals in concentrating on fine production. this question of range of yarn counts was introduced in connec- tion with the statistics of production, so that the figures for weight may require revision in terms of yarn grades and cor- responding values. = & . | competition with natural silk—up to the present the new cellulose product has made its own developments rather than entered into direct competition with silk. but competition has necessarily arisen, and there is in fact a recognised displacement in certain directions, and further progress must be estimated in terms of the capabilities of artificial silk, that is, of funda- mental qualities. obviously the most important is the ratio of weight to length. with this quality are directly associated the artificial silk covering power of the yarn as a weaving and optical effect, and, indirectly, the effects of softness and lustre. the present stage of development has been mainly realised on the basis of a unit thread of 5 to 7 deniers, which is a multiple of the “‘ size” of the natural silk. it is now established that the cellulose can be drawn to these dimensions and incidentally produced as yarn. the next fundamental point is that of specific weight, which is an ultimate characteristic of the respective substances; silk- serin has the density 1-23 and cellulose 1-53. the earlier spinning methods applied to viscose produced a cylindrical thread in close imitation of the natural fibre. im- portant technical progress resulted from study of the cellulose fibre in regard to form and contour as revealed by cross sections. with changes of the setting bath there were differentiations toward ovoid and kidney-shaped forms; by further correlating the stages of “ ripening” of the viscose with the conditions of the setting bath, it was found possible to exaggerate an irregular contour to one having deep indentation, the effect of which was to increase the perimeter by 50% above that of the regular cylinder of equal denier. the effect of this is the increase of apparent bulk of the thread, and of the covering power of the twisted multiple thread or yarn. the new element of technical control is a point of manifest superiority of the artificial pro- cess, since the added qualities of the thread and yarn compensate for the major defect due to greater density of substance. next in order are the mechanical and chemical qualities or properties which (1) are expressed as strength (tenacity) and elasticity, and (2) which condition resistance to the inevitable water-oxygen environment. tenacity and elasticity.—the earlier forms of lustra cellulose showed a specific tenacity of 1-0 to 1-4 grammes per denier, reduced to about 30% on wetting. technical progress has real- ised a substantial increase on these figures and especially in respect of ‘ wet strength” which reaches 60% of that of the original dry thread. ‘he statistical records of courtaulds, ltd., show a breaking strain in grammes per denicr of 1-2 to 2-2 dry and o-s to 1:1 wet. the variations are those conditioned by methods of manufacture together with the deniers of the unit thread. the present averages for the production of this firm are deniers 6 to 7, but with the range 3 to 11; the breaking strain is 1-5 dry and o-7 wet, in grammes per denier. in practice the true elasticity comes little into reckoning; the extensibility, or stretch, reaches 16 to 20%, which is of the order of the elongations of the natural silks under breaking strain. the results obtained from the observation kept over cellulose sub- stance yarns produced in the period 1895-1900 fully confirm the a priori assumptions of permanence of material, based on the actual chemical constitution of cellulose and the experience of its utilisation in various forms. it has been necessary to set out in some detail the fundamental qualities of the material as the primary conditioning factors. two others of scarcely less importance are self evident. the vis- cose process and products have the advantage in respect of costs of production and adaptability, representing a wide range of con- trolled variations in correlation with the wide and varying require- ments of the textile industry. lastly, the new material was launched into a world of already highly developed technical and competitive activity, ready to exploit the potentialities of the new product in the confection of the new fabrics, plain and mixtures, and in the auxiliary effects of decorative design and colouring. production.—the long-deferred realisation of the acetate “ silk ”’ is a postponement due to a number of interferences, in a sense accidental, amongst which was the world war; for the realisation was foreseen by the viscose pioneers and others, who recognised a priori a basis of first principles as the promise of achievement. thus the production of the acetate involves the simplest of factors; cellulose, carbon (coal), chalk and electrical energy. the product, as an ester, represents an increase of yield of 50% matter added by synthesis to the original cellulose; it has the relatively low specific gravity of 1°34; its combining relationships with dyestuffs are specific. a posteriori the celanese product proves to have a special form, divergent from the artillery cylindrical, and realising a high covering power. these, with other advantages, must be recognised as assuring industrial developments. on the other hand the process of spinning is elaborate, and requires a special cellulose raw material (cotton) specially prepared, and generally a higher scale of capitalisation and factory costs. these disadvantages have been increased under the present conditions of altered industrial values, and, moreover, the product has now to compete with its viscose rival, which is firmly established, and protected by the goodwill of routine consumption and the progressive development of textile quality and novel effects. waste products—it will be obvious that there are incidental waste products of the “ silk ” process as there are of the cocoon silks. the latter are in a form which can only be treated for mechanical separation of the fibres reduced to short length. these are graded and spun or twisted to the yarns known as schappe or spun silk. the fibrous wastes of the artificial silk process can be similarly treated. the results have led to a direct production, especially of the viscose silk, in short length, by reeling the thread as formed on bobbins of suitable diameter, and cutting through the mass of filaments which are liberated in calculated short length or staple. the fibre is known as “‘ staple fibre,” ‘ vistra,” “ fibro,” “ artificial wool.” it is spun usually in admixture by the methods required for discontinuous or ultimate fibre, e.g., wool, cotton. the silks, natural and artificial, are solid; in the production of the latter the viscous solutions are carefully prepared to be free from bubbles. the presence of bubbles leads to curious de- formations of the thread and defective yarns; on the other hand a study of these defects has led to the industrial production of the air-filled fibre—in the case of the viscose process by charging the viscose to its maximum with bubbles of air, and increasing the effect in the setting bath by the addition of compounds react- ing with liberation of gas (see cellulose). (c.. f.c.) bisliography.—j. foltzer, artificial silk and tts manufacture (1924); tubize artificial silk company, america, artificial silk (1924); a. h. hard, the silk and rayon (artificial silk) directory and buyers’ guide of great britain (1925, etc.). see also board of trade journal, london, march 1923; and articles in faserstoffe v. spinnpflanzen, vol. 6 (1924); kolloid 2, vol. 35 (dresden, 1924); textile merc., vol. 71 (1924); american silk jour- nal, vol. 44 (1925); dyer and calico printer, vol. 53 (1925); jour. of chemical soc., vol. 128 (1925); jour. text. institute, vol. 16 (1925); manchester guardian commercial (march 26 1925); meliand’s textilbertchte, vol. 6 (1925); suk journal (1925); textile worid, vol. 67 and 68 (1925). artillery (see 2.685). the old french word artiller, to equip with engines of war, is from the low latin artilare, to make machines. the english word ariillery dates from the early 17th century. it is now used to mean firearms of greater power than those carried by hand, and also the personnel who use them. the present article deals with the contemporary state of the artillery arm in land warfare. i. types of artillery the function of land artillery is to kill troops at a range beyond that of a hand weapon, and to destroy material, ob- stacles, and defences. various natures of artillory have been developed, suitable to the tasks to be fulfilled. these are:— field artillery. super-heavy artillery. medium artillery. anti-aircraft artillery. heavy artillery. trench artillery. field artillery —this is capable of accompanying the ad- vanced fighting line of an army. it consists of light guns and howitzers able to move at ro m. an hour on the road, and able to keep pace with infantry, or cavalry, in the case of the horse artillery, across country. it can come into action without pre- vious preparation of the ground, and, like all other natures of artillery, it can engage a target either from a position in the open by direct vision over the sights, or from a concealed posi- tion by means of angles of direction and elevation signalled from an advanced observing position or from an aeroplane. it consists of light guns and hght howitzers. | 225 the field gun is, in all armies, a piece throwing a shell of from 15 to 18 ib. to a distance of at least 10,000 yd., and weighing less than 30 cwt. in action. before the introduction of mechanical traction the weight was limited to 24 cwt. and the range to 6,000 yards. the present limit of 30 cwt. is due principally to the fact that this weight is as much as a gun-detachment of 6 men can manhandle. all modern field guns are quick-firing; that is, the gun recoils on the carriage and returns to the firing position, while the carriage remains steady. this saves the delay due to running up and relaying the gun after each shot, and increases the rate of fire from 2 rounds a minute to 25. it also enables the gun-detachment to remain behind the gun-shield, instead of having to stand clear of it during the recoil of the carriage. the field howitzer differs from the field gun in that it throws its shell high into the air, so as to descend at an angle of about 45°. this enables it to reach targets, such as men in deep trenches, protected from the direct fire of guns. since this high-angle fire requires less effort than direct fire, the field howitzer is able to fire a shell double the weight of that of the field gun, without exceeding the same weight of equipment. howitzer fire, from its nature, is local in effect, and at targets of considerable depth from front to rear, such as advancing in- fantry, it is far inferior to the flat-trajectory fire of guns. in most armies one-fourth of the field artillery consists of howitzers, and three-fourths of guns. special natures of field artillery are:— horse artillery, which can keep pace with cavalry across country. usually, for simplicity of ammunition supply, the gun is the same as that of the ordinary field artillery, but the weight behind the team is reduced by mounting the gunners on horses, instead of carrying them on the limbers and ammunition wagons. mountain or pack artillery is divided into separate loads which can be carried on pack animals or transported for short distances by hand. it is used in country impassable to whecled carriages, and is sometimes employed as artillery of accompaniment. the gun itself is divided into two pieces, forming mule loads not exceeding 320 lb., including 65 lb. of saddle and equipment. the old “screw-gun” used by the british mountain artillery was divided half-way down the bore, but the modern tendency is to divide the gun behind the base of the cartridge, so that the chase forms one load and the breech another. the carriage of a mountain gun has a cranked axletree, which is turned up- ward when firing at high elevations, so as to afford room for recoil without the breech striking the ground. in other respects the mountain gun is a smaller edition of the field gun, and fires a shell of 12 to 15 ib. to a distance of about 5,000 yards. moun- tain howitzers, firing a shell of about 22 ib., are also used. artillery of accompaniment.—the provision of a special light gun to accompany the infantry firing line is now a subject of controversy. a good specimen of the modern field gun is the u.s. 75-mm. gun, model 1921 on 1924 carriage (see fig. 1 on plate). this gun weighs 30 cwt. in action, and fires a 15-lb. shell ranging, with super-charge, 15,000 yards. with the normal charge the range is about 11,000 yd.; the super-charge, with stream-lined shell, is not used for ordinary fire, on account of the excessive wear which it causes to the gun. for the same reason it is probable that a reduced charge for ranges below 6,coo yd. will be intro- duced. flashless powder is used, and the shrapnel has a clock- work fuse. the carriage has hydropneumatic recoil gear of the st. chamond pattern, and a split trail, which permits of rapid traverse through a wide angle for the purpose of firing at tanks moving across the front. it allows of the gun being elevated to a high angle for firing at aircraft. although a field gun isnot a fully effective anti-aircraft gun, it is desirable that it shall be capable of engaging low-flying aeroplanes when these attack the troops with machine-guns. the wheels of the american field gun have rubber tires, to obviate, or at least to reduce, the damage to the equipment caused by tractor draught at a speed of ro m. an hour. the french 75-mm. field gun is a schneider model similar in essen- tials to the american gun. in england, armstrongs have a 226 1925 pattern 3-in. field gun rather more powerful than the american gun. vickers have a 3-3-in. 18-pdr. m.v. 2,100 fs., ranging 12,700 yd. with stream-lined shell and super-charge and weighing 30 cwt. in action. (see fig. 1). medium artillery.—this consists of guns and howitzers of greater range and shell-power than field artillery, yet sufficiently mobile to accompany the infantry advance. the usual types are a 4°7-in. gun firing a 5o-lb. shell to a range of 15,000 yd. and a 6-in. howitzer firing a 100-ib. shell to a range of 12,000 yards. the 4-7-in. gun is designed to fire upon distant road crossings, railway junctions and other important points which have to be engaged without delay, before the heavy artillery can come up. the 6-in. howitzer fires a powerful shell capable of demolishing buildings and of destroying entrenchments, other than those of a semi-permanent nature. it is the principal weapon used in trench warfare. both picces are available for counter-battery work, that is, for attacking entrenched guns which have been located by aircraft or by sound-ranging. the medium gun is an enlarged edition of the field gun. the 6-in. howitzer was formerly a short, handy piece, but owing to the increased range now required of it the length of the modern type is as much as 25 calibres. fig. 2 on plate shows a short krupp 6-in. gun used as a howitzer by the germans. this artillery super-heavy artillery.—as the size of a shell is increased, the effect increases in a higher ratio. much of the destructive effect of a 1,000-lb. shell is due to the blast, not to the local destruc- tion caused by the high-explosive charge. the effect of the blast is to bring down walls as much as 50 yd. from the point of burst, to cause roofs to fall in, and generally to wreck a great building such as a railway station or factory. a single hit from a 12-in. shell might destroy a bridge altogether, whereas ten hits from 6-in. shells, equal to the same weight of ammunition, would only cause easily reparable damage. a further advantage gained by the use of very heavy guns ts the greatly increased range. thus the british g-2-in. gun throws a 380-lb. shell 14 m., while the new u.s. 14-in. gun ranges 22 m. with 1,560-lb. armour-piercing shell, and nearly 30 m. with a somewhat lighter stream-lined shell. these considerations have led to the extensive employment of super-heavy pieces in land warfare. gun versus howitzer —formerly a howitzer was a low-velocity weapon fired at a high angle of elevation, while a gun was a high-velocity piece with a flat trajectory. the howitzer con- veyed the shell to the target with a much smaller propelling charge than the gun, and consequently lasted much longer than the gun before it was worn out. at present all guns are mounted fic. 1.—vickers 3:3-in., high velocity, 18-pdr. field gun (1925). would now be mounted on a carriage with split trail. the girdles on the wheels prevent them from sinking into the ground. feavy artiltery—this term is applied to pieces heavier than medium artillery, including guns up to 8-in. calibre and howit- zers up to g-2-in. calibre. in modern war it is necessary to attack objectives at least ro m. behind the fighting front, and accordingly road-mobile heavy artillery, which can engage targets beyond the range of medium artillery, has been intro- duced. the principal gun of this type is the 6-in. gun, the latest pattern of which ranges 15 m. with roo-lb. shell. it can be fired from the ground, without the delay entailed by building a plat- form; wire mats or similar appliances are uscd to prevent the wheels from sinking. modern 6-in. guns have split-trail car- riages to enable them to be traversed quickly. a howitzer heavier than the 6-in. is required for destroying bridges and semi-permanent entrenchments, the 8-in. howitzer fires a 200-lb. shell and ranges 18,000 yards; the brilish 9-2-in. howitzer, known in the war as “ mother,” fires a 290-lb. shell ranging 12,700 yd.; and the new american 240-mm. (9-45-in.) howitzer fires a 356-lb. shell to a range of 25,000 yards. ‘the latter piece is accepted as the typical modern heavy howitzer, and is about the largest piece likely to be transported by road in future warfare, as it is considered that heavier natures are better transported by rail. fig. 3 on plate shows a french schneider 6-in. gun, 1925 pattern, with rubber-tyre wheels, in- tended for tractor draught. a platform would be built for it if it were intended to remain long in the same position. so as to fire at high angles of elevation, in order to attain their extreme range, and use reduced charges as well as full charges and super-charges in order to save wear. on the other hand, the range required of howitzers is now greatly increased, so that the 1914 pattern, 12 calibres long, has been superseded by howitzers of 25 calibres and over, firing much heavier charges. the distinction between gun and howitzer is therefore tending to disappear. it may be said, generally, that where a high striking velocity is required, as in the case of an attack on armour, a so-calibre flat-trajectory gun is used; where the object is to convey a mine shell to the target, a 25-calibre howit- zer, with a powder-charge only sufficient to carry the distance at 15 degrees of elevation, is preferred. thus, in the world war, the french had a 520-mm. (20$-in.) howitzer throwing a shell weighing 1 ton & ewt. to a range of 12 m.; the germans had a 380-mm. (r5-in.) gun which threw an 8-cwt. shell 28 miles. the comparatively short range required of the 20}-in. howitzer is an instance of economy of force; it was built to fire from a railway mount, and the french reckoned that it could thus be brought within r2 m. of its prospective targets. the german 15-in. gun was transported by rail and fired from a permanent platform; its long range of 28 m. was necessary in order to bombard dunkirk from the german lines. for the same reason, its shell weighed only 8 cwt., whereas a typical 15-in. gun fires a shell of 17 cwt. to a proportionately shorter range. : super-heavy pieces are usually fired from railway mountings, or at least are transported by rail. but an invader may find artillery plate representative types of modern artillery fic. 1. american 75-mm. field gun (1921). fic. 2. german krupp 6-in. howitzer. fre. 3. french schneider 6-in. gun (1925). fic. 4. french schneider 4-2-in. anti-aircraft gun. fic. 5. british armstrong 12-in. howitzer, on railway mounting. (fig. 1. courtesy of u.s, ordnance dept.) artillery it necessary to bring up large howitzers, for the reduction of fortresses near the frontier, before the captured railways can be made available. the difficulty in the way of transporting these pieces by road is the limit of the weight which bridges can carry. even on the great main roads of western europe this weight is not more than 30 tons, and on country roads it may be as little as 5 tons. this implies a special type of howitzer, comparatively short and lght, capable of throwing a heavy shell to a short range. the german 42-cm. (16-5-in.) howitzer brought up for the siege of antwerp was only 12 calibres long, and weighed 213 tons, or about 29 tons on its special wagon. it threw a shell of 15-7 cwt. to a range of 10,300 yards. it was drawn by 3 traction engines, with a fourth in reserve for hills. the recoil gear, carriage, platform (in 2 parts), and gear for mounting the howitzer formed separate loads, and the piece required 13 traction engines altogether. the french have a 370-mm. (14-6-in.) howitzer, only 8 calibres long, throwing an 8-cwt. shell 11,500 yards. it is ren- dered road-mobile by being carried on 2 roacl-trucks, one follow- ing the other, with an arched girder between them from which the piece is suspended. the united states has a 9-45-in. how- itzer on a caterpillar mounting, driven by electricity from a separate vehicle which carries the 150-h.p. power unit. the total weight of the vehicle carrying the howitzer is 13 tons. long-range guns.—during the world war the germans bom- barded paris from a distance of 76 m. with specially built long- range guns, throwing 265-lb. shells. this long range was ob- tained by using a velocity of 5,000 fs. and firing at an elevation of 55 degrees, so that the shell passed through the layer of dense air nearest to the earth, and reached the comparatively thin air at a height of ro m. which opposed little resistance to its flight. in this case the greatest height of the trajectory was 24 miles. guns of this type cannot fire more than about 30 rounds before they are worn out. owing to uncertain weather condi- tions, the accuracy is poor; while the gun is new the shells may be expected to fall within a space of 2 m. long by 2? m. wide, but as the gun becomes worn these limits are soon exceeded. it is now considered that aeroplanes are more efficient than guns for this kind of bombardment, as an aeroplane can now carry a 2,000-lb. bomb and can drop it with far greater accuracy than the gun. | anti-aircraft artillery.—the problem of hitting a target mov- ing in three dimensions is a difficult one and the additional complication due to a curved trajectory has to be eliminated as far as possible. all a.a. guns are therefore flat-trajectory weapons, with muzzle velocities of the order of 2,000 fs. for light guns up to 3,000 fs. for medium guns. ordinary field guns mounted on lorries, as employed in the world war, are of little use. however, modern field gun carriages are built to allow of high angles of elevation, to fire upon low-flying aero- planes when these attack the troops with machine-guns. regu- lar a.a. guns are mounted on substantial pivots, with hydro- pneumatic gear to check the severe recoil. mobile guns, used in the fighting line, are usually on low, wheeled platforms, which can be drawn behind a lorry. on coming into action, the platform 1s lowered to the ground, and levelled by screw-jacks at each corner, so as to bring the pivot exactly vertical. semi-mobile guns, used in sedentary warfare, are on heavier platforms which are carried in sections and put together before firing; and non-mobile guns, for the defence of fortresses and cities, are on solid concrete or caisson platforms. mobile a.a. guns are usually 12-pdrs.; the greatest height of the trajectory is over 20,000 [t. and, up to 5,000 ft., the height at which reconnoitering acreplanes usually fly, the trajectory is very flat. semi-mobile and non-mobile guns are usually 4o-pdrs. of about 105 mm. (4-2-in.) calibre. this calibre is used principally to obtain a flat trajectory up to 10,000 {t.; the additional weight of shell does not materially increase the clfect. the ammunition used with a.a. guns is shrapnel or high- explosive shell; a proportion of the shells are fitted with tracers. a tracer is a small firework in the base of the shell, which leaves 227 a trail of smoke to mark its flight. this js necessary, since an ordinary shell fired into the air disappears until it bursts, and there is nothing to show whether it has passed close to the target or otherwise. the shell is fused so as to burst close to the target. if the fuse fails to act at this height, it explodes the shell at the highest point of the trajectory, so as to avoid en- dangering one’s own troops by the shell falling among them. fire at aeroplanes is entirely by prediction; the course and speed of the target are measured by optical instruments, and the gun is fired at the point where the aeroplane is expected to be, making due allowance for the time of flight of the shell. if the first shot or salvo misses, the plane will at once begin to dodge, and it is useless to fire at it until it has again settled down toa regular course. a good instance of the semi-mobile type of anti-aircraft gun is the french schneider gun shown in fig. 4 on plate. this is & 4°2-in. gun firing a 37-lb. shell with a muzzle velocity of 2,300 feet per second. the pivot mounting is fixed on a stecl platform, transported on wheels: the extensions carrying the screw-jacks are folded in- ward for travelling. the total weight is 8-8 tons. the over- head shield serves principally to conceal the movements of the detachment from above. the special feature of this gun is the control apparatus. this is an instrument which is set up at a suitable observing position affording a clear all- round view; it is electrically connected to the gun, and may be half a mile distant from it. six gunners tend the instrument, and observe the aeroplane with a_ short-base rangefinder and telescopes at- tached to the instrument, thus determining its range, height, speed and course. the in- strument translates these data into simple elements of eleva- tion and training of the gun. seen these are transmitted to the a : g. 2.— schneider c - gun by electric connections {10:27 schaller control 1 which actuate dials on the gun- mounting. the gun-detachment have only to follow up the reading of these dials with the clevating and traversing hand-whceels; they need not see the target at all. when the course of the acroplane has been determined, the officer at the observing position makes a “prediction”? of fhe point which it should reach, say 30 see. later, and directs his telescope on this point; the dials at the gun move forward accordingly. if the aeroplane duly appears on the cross-wires of the telescope, the officer fires the gun electriciuily; 1f it has changed its course in the meantime, a fresh prediction is mace. trench artlicry.—when two opposing forces are entrenched, they tend to press forward til thetr advancecl works are within too yd., or less, of cach other. the same thing occurs in siege warfare, when the besicger extends his front trench till it is close to the fortress. the need then arises for a weapon capable of throwtng a heavy bomb to a short distance, yet which is so small and light that il can be carried up through the trenches. the original piece of this type is the coechorn mortar used in the sieges of the 18th century. the medern type was introduced by the germans at the beginning of the world war. the krupp minenwerfer is a ight gun of 2-in. calibre mounted onashort plank. the 50-lb. spherical bomb rests on the muzzle, and has a tubular stcel “stick”? which extends down the bare of 228 the gun. the piece is fired at an angle of 45 to 75 degrees of elevation, and its extreme range is about 450 yards. the 50-ib. bomb, with its high-explosive charge, is capable of wrecking a “ dug-out ” or blowing in the walls of a trench so as to block it, as the weight of the 50-lb. bomb rendered ammunition supply, in the front trenches, a laborious proceeding, the british intro- duced the light stokes trench mortar, firing a 10-lb. bomb. this is a weapon of a different type. it is a light steel tube of 3-in. calibre, with a spike projecting into the breech end of the bore. the cylindrical bomb has a small cartridge and percus- sion cap fixed to its base; it is dropped into the muzzle, and slides down till the percussion cap strikes the spike, when the cartridge is ignited and the bomb blown out. the extreme range is about 1,200 yd.; this enables it to be used from a point well back in the trench system, where it is safer and less likely to draw fire than in the advanced works of the outpost zone. a 25-lb. stokes mortar was afterwards introduced, and was used principally for firing smoke shell. later on, the bombs were fitted with air-vanes to increase their accuracy. the 3-in. stokes proved such a handy weapon that it was used in mobile warfare as an infantry gun, for the reduction of “strong points” encountered in the infantry advance. being a high-angle weapon, it was useless against moving tanks. the french used the dumezil trench mortar, which is on the same principle as the krupp minenwerfer, but heavier. it throws stick-bombs of various weights, from 35 to 99 lb.; with the former it ranges over 700 yards. they tried a compressed air mortar, in which the range was determined by varying the pressure in an air-chamber; this was an efficient weapon, but was considered too complicated to manufacture in large numbers. the germans had a o-lb. trench mortar, ranging 1,400 yards, and in 1918 they adapted it so that it could be used as a mobile infantry gun, for direct as well as for high-angle fire. this isa miniature field howitzer, fired from a bedplate in the trenches and mounted on a small wheeled carriage for work in the open. heavy trench mortars.—owing to the difficulty of supplying heavy ordnance in sufficient quantities, trench mortars were introduced, in 1915, capable of throwing a 200-lb. shell about 1,200 yards. the principal piece of this type was the batignolles 240-mm. (g:45-in.) mortar. this is in two pieces screwed to- gether, and is fired from a mounting fixed on a bed of wooden balks. it is intended to be carried into the trenches on special iron barrows. the total weight is about a ton, and it is divisible into five barrow-loads. the allies used this weapon for firing from positions towards the rear of the trench system, where it could be turned on the front trenches in case the enemy invaded them. the germans used, for the same purpose, a rifled 170-mm. (6-69-in.) trench mortar, firing a shell of 110 lb. to a range of 1,250 yards. | ii. ammunition and transport all modern guns fire smokeless powder consisting of gun- cotton and nitro-glycerine in varying proportions. this powder makes a broad white flash at the muzzle of the gun, which en- ables the enemy to locate it, especially at night, unless the gun is behind cover extending at least 10 ft. above the muzzle. therefore field guns and other guns which have to be in action within s,ooo yd. of the enemy are now provided with flashless powder, which makes only a dull red glow. the flashless qual- ity is secured by adding certain ingredients to the smokeless powder. projectiles.—the most effective man-killing projectile against troops in the open is shrapnel shell, which is a steel case con- taining bullets and a small propelling charge. a time fuse, in which time is measured by a column of burning composition, or by clockwork, is set to ignite the charge behind the bullets when the shell arrives at a point about 50 yards from the enemy. the head of the shell is then blown off and the bullets released from the case which falls to the ground, the bullets going for- ward with the velocity of the shell at the moment of burst. however in the world war, in view of the enormous require- ments of ammunition and the predominance of trench warfare, artillery it was decided that the proportion of shrapnel should be con- siderably reduced. even field artillery, which, at the outset, carried at least 80% of shrapnel, were reduced to 5%, the re- mainder being common shell. the common or high-explosive shell is merely a hollow projectile containing high explosive, detonated on impact by a simple percussion fuse. it may be either thick-walled, producing effect by its splinters, or thin- walled (“‘mine”’) shell, containing a large burster for the de- molition of earthworks, etc. the former has an “ instantaneous” fuse which bursts the shell before it has time to penetrate into the ground, the latter has a “‘delay action”? fuse which allows the shell to penetrate some 6 ft. before exploding. special natures of shell are star shell for illuminating, smoke shell to conceal troop movements by obscuring the enemy’s view, incendiary shell, armour-piercing shell and chemical or gas shell, containing lethal or disabling gas. although the latter were used in the world war, their employment was condemned by the treaty of versailles, r919, and by the washington con- ference, 1922. whether they will be used in future wars is a question beyond the scope of this article, but it may be said that all nations are taking measures for defence against chem- ical warfare. | explosives are used for the bursting charges of shells. the substance principally used is picric acid, otherwise known as lyddite, melinite, shimose, etc. various substitutes, such as trinitrotoluene (trotyl) and ammonal are used on account of difficulties of supply (see explostves, military). efrfrect of shellfire the field artillery shrapnel shell discharges about 300 bullets, spread over a space of 150 to 300 yd. (according to the angle of descent of the projectile) from front to rear, and about 25 yd. wide. fire at troops is therefore so controlled that the lines of fire of the guns are 25 yd. apart and so that a shrapnel shell can be burst once a minute at least in front of each 25-yd. unit of target. this is the normal rate of field artillery fire, and the rates of barrage fire are based on this. the rate may be re- duced for fire of interdiction, or doubled or quadrupled at deci- sive moments. or the lines of fire may be concentrated, so that the fire of several guns converges on one target, when attacking a single gun or group of machine-guns. common shell, when used with instantaneous fuses against troops in the open, is less effective than shrapnel, but its moral effect is greater. bombardment.—effect on earthworks depends on the mine- power of the individual shell, as measured by the size of the crater which it produces. for instance, a 6-in. howitzer mine shell, containing some 13 ib. of explosive, produces a cylindrical crater about four yards across and 10 ft. deep, partly filled up by earth falling back into it. therefore to breach a 12-ft. parapet it must be struck by one such shell per 4 yards. if the diameter of the crater is less than the thickness of the parapet, great waste of ammunition ensues; for this reason field gun and field howitzer shell are practically ineffective against entrench- ments. at guns in the open, a modern field gun takes 15 rounds of shell at 3,000 yd., or 25 rounds at 3,500 yd., to make a dis- abling hit. wire cutting —defensive belts of barbed wire are a leading feature of modern defences, and it is of great importance to provide means of cutting lanes in them for attacking troops to pass through. in 1915 this was done by the precise and delib- erate fire of shrapnel, and had to be carried out on the day previous to the attack, thus forfeiting the advantage of surprise. the introduction of the instantaneous fuse for common shell has enabled wire-cutting to be done quickly, but a large ex- penditure of ammunition is still required. the french found in 1918 that 600 rounds of field common shell were required to cut a lane 25 metres wide through a belt of strong wire 25 metres deep at ranges of 2,000 to 4,000 metres. the time taken was 15 min., after ranging had been completed. fire at tanks.—any gun, down to a 6-pdr., is capable of dis- abling a tank with a direct hit at ranges up to 2,000 yards. at longer ranges, field and mountain guns have to be provided with artillery armour-piercing shell to attack armoured tanks. the 18-pdr. field gun will penetrate about 2} in. of armour at 1,000 yd. and 13 in. at 4,000 yards. fire at armoured forts ——the belgian forts destroyed by the german super-heavy artillery in 1914 were not attacked by firing at the armour, but by undermining the armoured turrets with mine shell which exploded in the earth under them. it has been proposed to obviate this by covering the ground in front of the turret, to a distance of 50 metres, with an apron of cast-iron blocks one metre cube, which will burst the “ under- mining’’ shell harmlessly on the surface. armoured forts are very vulnerable to gas attack and to heavy bombs dropped from aeroplanes, and it is probable that, in future land defences, they will be replaced by entrenchments. supply of ammunition modern methods of warfare developed in the world war necessitated the employment of enormous quantities of artillery ammunition. thus in aug. r918 the germans had over 30,000,- ooo shells in their ammunition columns and depets in france. in 1914 it was considered that 1,500 rounds per field gun should be in hand at the beginning of a campaign; of these, on the average, 300 were carried with the battery, 100 in a light ammu- nition column capable of moving across country, and roo ina heavy ammunition column. the remaining 1,coo were kept ready in arsenals. it was soon found that this allowance was insufficient. it was found necessary, for a great attack, to put in one field gun per ro yd. of a 50-m. front, and in view of the fact that each gun might have to fire 500 rounds in a day, the old methods had to be revised. the solution was to bring the daily output of the arsenals as close as possible to the fighting front, by using ordinary railways, light railways and specially- laid trench railways. the ammunition columns, which now consist entirely of motor lorries, are no longer looked upon as reserves of ammuni- tion, but as carriers between the advanced ammunition depets, called dumps, at the various railheads and the guns. they formed advanced dumps by the roadside as near as possible to the gun positions, and the battery ammunition wagons took the ammunition up to the guns. the view of those who base their ideas on the world war experience, is that before an action each gun should have 300 rounds beside it, in addition to the number carried in the battery wagons. the railhead dump is usually at least 5 m. behind the guns, to secure comparative immunity from fire, and the motor ammunition columns are expected to make 4 double trips a day, covering 4o to 50 m., besides the additional ground covered in an advance. special artillery vehicles are no longer used in ammunition columns; these consist mainly of civilian motor vehicles, either lorries or stripped chassis fitted with platforms. in principle, all transport has to be “ general service,” capable of carrying ammunition, stores or troops, as required. at the gun itself, a shielded ammunition wagon, containing about 100 rounds, is run up beside the gun, forming a protection for the gunners employed in setting fuses and in passing shells to the loading number. transport of artillery at the present time the draught horse is in process of being replaced by mechanical transport for all artillery. this change is necessarily a gradual one, and its nature and progress in different countries are partly determined by the extent to which the mechanical transport which has replaced the horse in civil life can be rendered available for military purposes. artillery may be mechanicalised in several ways. the auto- mobile gun-carrlage has the gun-mounting built into it, and is preferably of the “ caterpillar” type. the artillery tractor pulls the gun behind it, and carries the detachment and first supply of ammunition, and the artillery carrier carries the gun on a platform from which it ig dismounted, by a ramp, for firing. from the tactical point of view, the automobile gun-carriage is at the moment not satisfactory, as it is too vulnerable and too 229 large for concealment, and requires an undue amount of labour to entrench. the motor is useless while the gun is in action, when, if it were separable from the gun, it would be most useful in bringing up ammunition. tractors.—the artillery tractor may be a caterpillar or a vehicle of the lorry type. both forms are open to the objection that the complicated mechanism of a q.f. gun is damaged by rapid travelling on the road, even if the wheels be provided with rubber tires. the caterpillar tractor is good across country, but cuts up the roads; the least unsatisfactory in this respect is the tractor of the french kegresse type, with rubber cater- pillar bands, which are said to last as long as linked steel bands. on the other hand, the rubber bands do not grip so well as steel ones on slippery ground. various attempts have been made to construct tractors and carriers having both road wheels and caterpillar tracks. the american christie tractor travels normally on road wheels, and has a caterpillar band which is put on round the wheels for cross country work; the french st. chamond carrier-tractor is a complete caterpillar vehicle, with an extra pair of road wheels on extensions of the chassis at each end, which can be raised well clear of the ground, allowing the vehicle to rest on the caterpillar tracks. another vehicle, of a different type, is the “ 4-wheel drive” lorry, in which the wheels are driven independently. this is excellent on the road, and is capable of moving over easy country. but, owing to the extra complication and expense, the civil demand for it as a vehicle is very small. the pavesi agricultural tractor is a small, 4-wheeled vehicle with a flexible connection between the fore and hind carriages, which enables it to adjust itself to irregularities of the surface of the ground. its 4 wheels are driven independently, and have removable “spuds” which are put on for cross-country work. it has a 16-h.p. engine burning paraffin or petrol. the road speed is about 5 miles an hour, and the machine is therefore unsuited for the rapid trans- port of reserve field artillery. it has, however, been adopted for the italian divisional artillery, and it is under consideration as the tractor for the french artillery of accompaniment. the artillery carrier saves the gun from road strains, but en- tails delay in lowering the gun on to the ground when it comes into action, and in hoisting it up again with a ramp and winch, many tractors, such as those of the american holt type, can be fitted with platforms and used as carriers. it is not prac- tically possible to fire the gun from the carrier, as this would entail a considerable increase of weight and complication. any commercial lorry can be readily adapted as an artillery carrier, for travel on the road only, by the addition of a winch. as regards the difficulty of combining a road vehicle and a cross- country vehicle, the carrier is subject to the same disadvantages as the tractor. french and italian practice—the french, in 1920, proposed to introduce an agricultural tractor, encouraged by a govern- ment subsidy, which should be available for the transport of artillery. but it was found that owing to the small size of ficlds in france there was little demand for the tractor, and no immediate prospect of its superseding the horse. on the other hand, the use of motor-lorries is extending rapidly. the french have now decided to carry the army field artillery, which is re- quired to be highly mobile, on lorries, thus accepting the prin- ciple of the carrier, not the tractor. these lorrics cannot move off the road, except on favourable ground; therefore each battery carries a pair of draught horses per gun on its lorries, to take the guns into position. the french had 83 of these batteries portees at the end of the war. the french gun of accompani- ment, at the rate of 2 per battalion in the fighting line, is to be drawn by a small agricultural tractor of the pavesi type stand- ing about one metre high. the italians have arrived at a somewhat different solution. no draught horses are bred in italy; they have to be imported from germany. it has therefore been decided that the divi- sional field guns are to be drawn by the pavesi agricultural tractors already described. the italian army field artillery, which is required to be highly mobile, will be carried on low 230 platforms, which have springs and rubber-tired wheels, pulled by fast lorries. when the guns have to leave the road, they will be taken into position by the divisional pavesi tractors. the americans have finally condemned the automobile gun- carriage, and favour the caterpillar tractor. they consider it possible to produce a pattern of caterpillar band which will not cut up the road unduly. other nations are still experimenting. medium guns are usually tractor-drawn, the gun being shifted to a “travelling ” position in which the weight is divided between the gun wheels and limber wheels. heavy guns are transported on special wagons, drawn by tractors, which carry the piece itself, while the empty carriage is drawn by a second tractor. super-heavy artillery is transported almost entirely by rail, though in 1914 the germans brought up their siege howitzers, divided into separate loads, on special road-wagons. the rail- way mounting consists of a massive platform supported by bogies, on which the gun mounting is built (see fig. 5 on plate). in the english elswick type the gun is fired while the mounting is ‘‘alive’’ on its wheels; in other types the central platform is lowered on to the rails before firing. all-round fire from the truck, without special preparation, is only possible with medium guns; for heavier natures the gun is laid for direction by running the truck up or back along a curved siding. or, in some railway mountings, the gun-truck is supported laterally by heavy “ outriggers”’ sunk in the ground. for the heaviest natures the railway is used for transport only, and the gun js lowered on to a previously built platform. permanent concrete platforms were used in 1914, but these were superseded by “‘caisson”’ platforms consisting of iron boxes bolted together and filled with earth, surmounted by a steel platform plate which carried the mounting. recent american platforms dispense with the caissons, and consist of the plat- form plate only; this is divided into sectors for transport, bolted together on the spot, and pegged down with a number of steel stakes. these platforms can be laid in a few hours, this being a great addition to the value in the field. railway mountings can be used for the transport of artillery on light railways, and even on trench railways. additional narrow-gauge wheels are fitted to the gun-truck for this pur- pose. in this case a platform must be used for firing. the limit of the height and width of a railway mounting is the load- ing gauge of the railways on which it may have to be used; this depends principally on the size of the tunnels. practically there is no limit to the length or weight. 7 iii. technique and organisation in modern war, guns are quickly silenced if they come into action in full view of the observing posts of artillery already in position. except in special cases, as that of guns of accompani- ment, artillery always use the concealed position behind a ridge or other cover from view, in which the elevation and direction necessary to hit the target are signalled by an advanced ob- server. an acroplane may be used, when available, to correct the fire; modern developments of wireless telephony enable the airman both to send and to receive messages: advanced observers on the ground now use “ground wireless” instru- ments. it is now considered that with wireless telegraphy, which is more reliable than wireless telephony, it is possible to use’one instrument per 500 metres of front without interference. ranging.—this process serves to determine the elevation at which a gun will hit the target, or, more correctly, the eleva- tion at which the mean point of impact of the shells will coin- cide with the target. this elevation is not necessarily that due to the map range, as it is affected by the tempcrature, height of barometer, strength of the powder, degree of wear of the gun and other factors which together constitute the “error of the day.” when a number of shells are fired from a gun which is pointed at a given elevation above the target, they do not fall in the same place, but are distributed over a space which, at medium ranges, may be 100 yd. in depth. ‘together they form a“ sheaf of fire.”’ the first step in ranging is to determine, by observation artillery of the fall of the shells, 2 elevations, at the higher of which the sheaf of fire will fall beyond the target, and at the lower of which it will fall short. these 2 elevations must be such that the sheaves of fire do not overlap, as otherwise they would afford no definite information. the 2 elevations constitute the “long bracket,”’ within the limits of which the true elevation must lie. the usual long bracket is one of 300 yards. this bracket is then “‘split” by firing at the 2 intermediate hundreds of yards, and observing the results, thus obtaining a closer approxima- tion to the elevation required. finally, corrections of 25 yd. are made till an equal proportion of rounds are observed to burst over and short. ranging for line, that is, for lateral direc- tion, is carried out in the same way. map ranging.—it is of great importance to be able to open effective fire by surprise, without preliminary ranging. it is possible to do this if the exact map range, and the factors con- stituting the error of the day, are known beforehand. in position warfare the ground is accurately surveyed, and the em- placement of each gun is marked on the survey. guns are care- fully “calibrated,’”’ a process which consists in determining the error due to wear by firing at a known range. the error of the powder is measured in the same way. a special section in each army corps, known as “‘ meteor,” keeps the batteries informed as to the atmospheric conditions. by this method it is possible to open effective fire without ranging, even on unseen targets, with sufficient accuracy for purposes of bombardment. map ranging is hardly applicable to mobile warfare. another method of ranging, much used in trench warfare, is the employment of a “ witness point.” this is an easily observed point in the enemy’s lines, such that its range can be measured exactly; it should be in the general direction of the prospective target, and within about soo yd. of it. by firing a few prelimi- nary rounds at the witness point, and observing the result, the data necessary to hit the target can be obtained. sound rainging.—this is effected by observing the moment at which the report of an enemy gun, or the burst of a shell fired at it, reaches each of a chain of recording instruments, it has recently been improved so as to give very accurate results under suitable weather conditions, from a set of instruments occupying as little as 2,500 yd. of front. setting up the instru- ments takes the rather lengthy time of from 24 to 48 hr., which limits the employment of this method in mobile warfare. (see sound ranging.) the proportion of field artillery to infantry in an army was for long fixed at about 6 guns to 1,000 rifles, and inlantry divisions were formerly organised on this scale. it was found, however, that this proportion of guns was excessive for seden- tary warfare, and utterly insufficient for active warfare. a modern division has therefore only 4 guns per 1,000 rifles, the 2 additional field guns being formed into mobile “ army ”’ brigades to be put in as reinforcements where required. a division has one battery of medium guns for long-range work: heavy guns and howitzers, which can fire over a front exceeding that of a division, are allotted to army corps; and super-heavy guns are under army command. the proportion of artillery of all natures arrived at by the end of the world war was ro guns and howitzers per 1,000 rifles, roughly 6 field, 2 medium, 13 heavy, and 3 super-heavy. this did not include the trench mortars, at the rate of one per tov yd. of front, used in trench warfare. the usual field artillery fire unit 1s the battery si 4 guns, which is capable of firing roo rounds a minute on emergency. six-gun batteries are sometimes used for the sake of economy, as they require proportionately fewer officers and battery stafis. field batteries are organised in brigades (french groupes, german a beeilungen) usually of 3 gun batteries and one howitzer battery. medium artillery work in single batteries of 4 guns, heavier natures work singly. prior to rot4 the highest artillery command was that of the divisional artillery, but when the artillery of a given front had to be increased to treble its normal strength, for attack or de- fence, it was found that a higher artillery command was artillery required. the g.o.c. the artillery of an army corps of 3 divisions (sometimes 4), now commands the 3 divisional artilleries (rein- forced if necessary by army field artillery); the corps artillery (also reinforced); and any super-heavy artillery allotted to him for the operation. iv. tactics of artillery in modern war it is found that infantry units opposed to each other are driven to seek cover, and immobilised, as soon as they get within the zone of each other’s aimed fire. their only means of arriving at a tactical decision is to enlist the aid of an arm which is capable of keeping down the fire of troops opposed to them while itself keeping beyond the range of effec- tive rifle fire, or which is capable of withstanding rifle fire, as in the case of shielded guns and tanks.! the assistance afforded to the infantry by the artillery during the world war was so effective that the artillery came to be regarded, at least until 1918, as the most important arm, although it is incapable of achieving victory by its own efforts. before 1914 it was held that infantry and artillery should work in intimate co-operation (/iaisen) so that when an infantry unit was checked it could at once communicate with the artillery behind it, and inform them as to the exact points which the in- fantry required to be shelled. the first battles of the world war showed this ideal to be impracticable, as communications broke down at once. neither telephoning, visual signalling nor communication by orderly, were possible under heavy fire. in addition to this not even the infantry themselves were capable of locating the enemy which was causing them casualties. when troops were in permanent trench systems, telephonic communica- tion, by deeply laid cables, was maintained; but the moment the infantry advanced or retreated from their trenches they lost touch with the guns. barrage.—this led to the introduction of the barrage, which is a screen of bursting shell across the whole front of the infantry advance. the smoke and the dust thrown up conceal the in- fantry and protect them from aimed fire. the “creeping” bar- rage is advanced according to a time-table, by “ bounds ” of perhaps too yd.; it is “halted ”’ on each successive objective to ‘pound ”’ it before the infantry assault it, and when the final objective is attained it becomes a “standing” barrage to screen the infantry while they consolidate the position. the infantry follow the creeping barrage closely, keeping just behind the zone of bursting shells. it is intended that the barrage shall destroy all opposition, but however dense and however deep the zone of bursting shells is made, this is almost impossible to attain, as infantry and machine-gunners take refuge in deep trenches while the barrage passes over them, and then re-appear. the objections to the barrage are serious. it cannot be put down without considerable delay and once started, it cannot be controlled. moreover, since it has to be fired by a large num- ber of dispersed batteries, 1t is impossible to communicate with them all, through a “ chain of command,” in time to check it if the infantry are unable to keep up with it. since the whole area of the advance has to be covered progressively with bursting shells, the greater part of these are ineffective, except as contrib- uting to the smoke screen. it requires elaborate preparation and a very heavy expenditure of ammunition. the modern tendency is therefore to restrict the barrage, and the number of guns detailed to fire it, to the minimum required for safety; that is, to form a protective rather than a destructive barrage, and to employ as many guns as can be rendered available in accurate fire at important targets in and behind the enemy’s line. it is obvious therefore that when a situation demands a barrage, the fight has temporarily become of a stationary nature. the creeping barrage is also used to screen retreating troops; a “‘flank ” barrage screens the flank of troops halted or on the move, and a “standing ” barrage is used for many purposes, such as to prevent the enemy from reinforcing the portion of his line which is being attacked. the barrage, with all its defects, is necessitated by the impossibility, under present conditions, of 1 (as warfare is not here considered. | 237 communication between units on the battle-ficld. should wire- less telephony be so developed as to be directive, selective and proof against interference, the crude method of barrage may disappear. mosilte warfare the creeping barrage may not be sufficient to overcome all opposition to the advance, and the infantry are liable to be held up by machine-guns and troops protected by overhead cover. it is necessary that they shall be accompanied by artillery, fol- lowing the firing line so closely that they can see what is going on, and can open fire on machine-gun nests, etc., without the delay caused by signalling messages. guns of accompanimeit—so much is generally admitted; but the nature, command and organisation of the accompanying artillery are matters on which opinions differ. moreover, the infantry are not satisfied with guns of accompaniment, but demand a weapon of their own in the actual firing jine to deal with sudden attacks by tanks and machine-guns. it is impossible to go into the whole controversy in this article. the opinion of the french, which carries great weight, is as follows:— the artillery of accompaniment must have a fully efficient shrapnel weapon; miniature guns arc of little use; the gun will be the service 75 mm. field gun on a low carriage, and will be taken into action by a small tractor standing less than one metre high. it may have a special light shell to facilitate ammunition supply. the artillery will be tactically under infantry command, but will be free to choose its own technical methods. other nations are introducing pack guns, or special light guns or howitzers which can be drawn as far forward as possible by small tractors, and can then be divided into loads and carried up by hand. the british gun of accompaniment is at present the 3.7-in. pack howitzer, but it is generally considered that its 20-lb. shell is so heavy as to present serious difficulties in am- munition supply. the infantry gun, as distinguished from the artillery of accom- paniment, will probably be a small piece firing a shell of about fic. 3.—schneider r-in. anti-tank machine-gun, tt lb. capable of stopping tanks up to 1,000 yd. range, and of destroying machine-guns. it will be on a low sleigh mounting. this is in effect a development of the elephant rifle issued to the german infantry as a tank-stopper. the recoil of this rifle was too severe for firing from the shoulder, and it was in process of withdrawal and re-issue as a machine-gun at the end of the war. fig. 3 represents a schneider one-inch machine-gun firing armour-piercing shells, intended especially for stopping tanks. phases of the world war the world war was divided into four phases: the invader’s dash into enemy country, a long period of trench warfare, the breaking of the line, and the retreat of the invader. it is of the utmost importance to the invader to make his initial dash so rapid and effective as to finish the war at once; similarly the defender hopes to drive back the invader without entcring on an exhausting period of sedentary defence. therefore both sides must be able to dispose of highly-mobile troops and the light and medium artillery must be able to keep pace with an advance at the rate of 50-100 m. per dav. | saltents and re-entrants—the tactical method will be, as heretofore, the rapid deployment of a superior force of infantry and artillery wherever opposition is encountered. the length of the battle-front will be measured in hundreds of miles. the battle-front will naturally assume an indented shape, with salicnts where slight opposition is encountered, separated by 222; re-entrants where the resistance is obstinate; these salients will be fed by reserves so as to spread out laterally and to encircle and pinch out the re-entrants between them. in this warfare the light artillery is relied upon to form the salients, while the heavy and superheavy artillery, the latter ranging about 30 m., bom- bards the re-entrants and renders them untenable. the attacking force is preceded by a screen of motor-cyclist infantry supported by light artillery. this force moves about 20 m. in advance of the main body; its function is to conceal the movements of the main body, to overcome slight resistance, and to locate the positions taken up by the defending army. the object of including artillery in this force is to overcome resistance with which the combat troops (e.g., mechanicalised infantry or tank infantry) cannot cope; thus a machine-gun in a house com- manding a bridge or defile might hold up infantry for hours, whereas a field gun would wreck the house in a few minutes. it is necessary that the artillery accompanying this force shall be highly mobile, in order that it may be brought to any point where resistance is experienced with the least possible delay. some authorities consider that it is worth while to introduce an automobile gun for this purpose alone, in spite of the objections to it already mentioned. in any case it must be a piece capable of a higher degree of mobility than that required of the divi- sional artillery. deployment.—wherever a defensive position is located by the advanced screen, and the aeroplanes which accompany it, the long columns in rear deploy as quickly as possible. the attacker cannot tell how serious the resistance will be, but if he under- estimates the strength of the defence, and delivers an attack with insufficient artillery support, he exposes himself to a severe check. his safest course is to prepare for an attack en regle, preceded by an artillery bombardment, led by tanks, and pro- tected by a barrage.! this entails bringing up a large supply of ammunition, since each field gun should have 300 rounds “dumped ” beside it, in addition to the supply that is carried with the battery. further, it entails reinforcing the artillery on that particular front to ‘‘ attack strength ” of one gun per ro yd. of front, by bringing up artillery from the reserve and from neighbouring columns. this is because one field gun can only barrage 30 yd. of front effectively, and because only one-third of the guns are available for barrage purposes, as will be seen. the deployment and formation of artillery dumps will take at least 24 hr., and the attack will take another day, from dawn to dusk; after all this preparation and delay the attacker may find that he has deployed against a sham position, and wasted time and ammuni- tion. he is therefore tempted to endeavour to rush the position with his advanced guard, a proceeding which affords great opportunities to an alert defender. supporting artillery—as regards the action of the support- ing artillery, that of the guns of accompaniment has already been referred to. of the remainder, one-third of the guns will bombard and afterwards barrage; the other two-thirds, includ- ing all the medium and heavy guns available, will bombard the position and will afterwards concentrate on important points in the defender’s line and on objectives such as cross roads and railway stations in rear of it. the french regulations of 1912 advised deploying only a sufficient number of guns for the immediate purpose in view. but it is now generally considered that the german method is preferable; this consists of getting all the batteries into position, ready to open fire if required, as quickly as possible. one reason for this preference is that a battery in action in a concealed position is much safer from fire than if it remains in column on the road, where it can be located by aeroplanes. defensive positions —the local conduct of the attack con- sists in forming salients wherever the infantry or other combat 1 this and most of the subsequent detail is inevitably based on the conditions of the world war and is thus liable to be radically modified by the mechanical evolution which is taking place in all armies. further it visualises a scale of artillery support which 1s beyond the means of the british army, at least under its post-war organisation. artillery troops can get forward, feeding the salients with reserves so as to form offensive features, and surrounding and “ pinching out ” the re-entrants between them. a modern defensive position is not a well-marked continuous line, which would be untenable under artillery fire; it is a chain of small centres of resistance, or localities organised for defence, each as inconspicuous as possible, held by detachments varying from a platoon to a company with machine-guns. these defended localities and the posts compris- ing them flank and support each other by their fire; they are <sktirorie = “ty nyy yy yp py pf [tpi fic. 4.—the penetration of a position. a, weak salients liable to be cut off; b, salients fed by reserves, and pinching out re- entrants. protected as far as possible by obstacles, but they cannot be provided with barbed wire and overhead cover as in a regular system of entrenchments. each of these centres of resistance has to be taken, or en- veloped and cut off, by the attackers, and for this they require the assistance of the guns of accompaniment. for the fighting is too confused and complicated for the divisional artillery in the rear to afford much help to their infantry at this stage, especially as the enemy posts, being carefully concealed, often remain undiscovered till the infantry are close upon them. however, the divisional artillery must press forward as their infantry gain ground, keeping in touch with them as closely as possible. aeroplanes, dropping messages, will assist in keep- ing up communication between the infantry and the guns. if the infantry are seriously checked, and have to await reinforce- ments, the divisional artillery must be prepared to put down a barrage in front of them. medium and heavy guns gain little artillery by advancing to a shorter range, and their fire is interrupted while they are moving; consequently they do not usually ad- vance till several miles of ground have been gained. a fully-organised defensive position may be 4 or 5 m. in depth, consisting of several successive chains of defended local- ities. as each of these is taken by the attack, the bombardment, which has been “lifted ” at the moment of assault, is shifted to the next line of defences; these have hitherto been invisible to the artillery of the attack, but are now in view of the advanced artillery observing officers, who press forward to the first-line positions as soon as they are taken. the infantry advance is resumed (usually by fresh troops); a fresh barrage is started, and the attack pushes on till success is achieved, or till the attacker’s forces are exhausted. in modern warfare there is no question of keeping any of the attacker’s guns in reserve to cover a possible retreat; it is con- sidered preferable to use all the available gun-power to strengthen the offensive. | pursuit of the enemy—after a position is captured, it is most important to keep up pressure on the retreating enemy, in order to convert his retreat into a rout. horse-drawn artillery is usually too exhausted to pursue, but motor artillery can go on as long as its petrol lasts. the pursuit is one of the few occasions when artillery should fire at night; even if accurate fire is impossible, a few shells taking effect on the men and transport of a crowded column will do a great deal to lower the enemy’s morale. the strategy of the defender consists mainly in keeping the attacker in ignorance of the real defensive position; he is thus induced to deploy prematurely against sham positions lightly held by mobile troops and guns, so that the defender can counter- attack his weak, extended line with a strong, concentrated force. here, again, a high degree of mobility is required in order to assemble the field artillery quickly enough to take ad- vantage of any momentary weakness in the attacker’s line. the same principle applies to the tactics of mobile defence. the attacker’s communications are impeded by long-range shell fire, which hinders him in bringing up his reserves and heavy artillery, and his advancing infantry are weakened by shrapnel fire. wherever the defender can secure a superiority of force he delivers a counter-attack, protected by an artillery barrage and supported by accompanying and divisional artillery. similarly, in the defence of the real position, the defender endeavours to conceal his trenches and defended posts, and thus save them from concentrated artillery fire, till the attacking infantry arrive within short rifle range of them, and are mowed down by machine-guns which have hitherto been kept silent. the defending artillery have the advantage of knowing the ground and the precise range of every point in their defences, and must do their utmost to keep up communication with their infantry, in spite of the damage to telephone lines caused by the bombardment. (the “ ground wireless ” instruments already referred to may here be most useful.) therefore they should be able to deliver sudden bursts of fire on the attacking infantry at critical moments, and to afford efficient support to local and general counter-attacks. artillery in trench warfare as the invader advances into the enemy’s country, the hastily mobilised defending forces will grow stronger, and the resistance will become stiffer. if the defender succeeds in assembling a force nearly equal to that of the invader, and in establishing it in a strong, entrenched line, before the invader reaches the capital or other vital point, there will then ensue a period of trench warfare. a modern entrenched line consists of a forward or covering zone some 2 m. deep, consisting of small detached works lightly held, intended to delay the enemy, to break up his line, and to mask the defences in rear; a main zone of strong detached works capable of all-round fire, connected with each other by a chain of short lengths of trench and with the troops in rear by communication trenches; and a reserve zone or second line, 233 which must be far enough in rear to compel an enemy who has penetrated the main zone to form up for a fresh attack. when both sides are comparatively inactive, the field artillery defending the line is kept at its minimum defensive strength of one gun per 30 yd. of front, of which one-third is in the main zone for the defence of the covering zone, and two-thirds in positions in rear for the defence of the main zone. heavier natures are still further in rear, in positions where their long range enables them to cover a wide front. the work of artillery in routine trench warfare is to exhaust the enemy’s strength by inflicting constant losses on him, and to take part in the daily minor engagements between the cover- ing zones. these daily combats are necessary to prevent the defence from degenerating into mere passive resistance, to keep the enemy on the alert, and to prevent him from withdrawing troops in order to strengthen his offensive on other fronts. counter-battery work is constantly carried on, the enemy bat- teries being located by flash-spotting, sound ranging and by observation from aeroplanes and captive balloons. since any battery which has been located will be shelled out when the line is bombarded, as many batteries as possible are kept in “silent positions,” from which they are not allowed to fire; the daily work of harassing the enemy is carried out by a com- paratively small number of guns. breaking the line it is useless to break through on a narrow front, where the troops who penetrated the line would be exposed to artillery fire from both flanks. the germans, in april 1918, attacked on a front of 50 m., and for this attack they assembled about 9,500 guns and howitzers of all calibres, mostly field guns, or rather more than one gun to every 10 yd. of front. their attack was pressed home only on alternate sections of about 3,000 yd., so that the fire of one gun per 5 yd. was concentrated on the real fronts of attack. instead of a week’s bombardment, as in pre- vious battles, the opening bombardment was compressed into 6 hours of rapid fire, gas shell being used against the front trenches, and high-explosive shell against important points up to 10 m. in rear. wherever the infantry penetrated the front line they were accompanied and closely followed up by field artillery. the lead- ing features of this attack were the “ surprise ”? bombardment and the bold use of accompanying and supporting field artillery. the former was due to the development of ‘‘ map ” firing, which enabled preliminary ranging to be dispensed with. in future battles an even shorter bombardment may be used, especially if tanks are available to break through the barbed-wire defences. the main difficulty in the operation of breaking the line is that of assembling a sufficient force of infantry and artillery on the front of attack without the enemy’s knowledge, or so quickly that he has not time to collect an equal force to oppose it. the normal artillery strength of the front has to be trebled. positions for the reinforcing batteries have to be prepared, telephone cables laid and buried and ranges measured, so that a fully effective bombardment can be opened suddenly, without warn- ing, on the day of attack. the assault may have to be driven home to a depth of 50 m. before the defender’s line is broken so that troops can pour through the gap, and this implies that preparations must be made to push forward guns and ammuni- tion over the battle-field (which is probably a mass of shell-holes, with all roads and bridges destroyed) so as to maintain an unre- mitting pressure on the defender and prevent him from disengag- ing his troops and forming them up for a fresh stand. it was the difficulty of bringing up men, guns and ammunition over the battle-field that brought most of the attacks in the world war to a standstill. tactics of attack.—the tactics of the attack.on an entrenched position are much the same as those of the attack on a position in mobile warfare. the points of difference are: (a) the details of the defences are definitely known from aerial photos; (5) the obstacles, such as barbed wire, are more formidable; (c} the defenders will have plenty of deep “ dug-outs, ” so that the bar- rage and bombardment will be less effective. the first point 234 implies that the bombardment can be concentrated on definite points, instead of being more or less spread over the country; the second requires that field guns and, if possible, tanks, must be pushed forward to cut the wire; the third is simply a matter of plenty of heavy howitzers. generally speaking, the result of an attack on the grand scale is a matter of strategy rather than tactics, and depends on the relative strength of the forces (especially artillery and tanks) which the combatants are able to assemble on the front attacked. if the ‘defender is able to reply to the bombardment with an equally effective bombardment, and to the barrage with a counter-barrage, no decisive result can be obtained—by in- fantry at least. failing this, the defender must give ground without allowing his line to be broken, remembering that every mile of advance increases the difficulties of the attacker, till the impetus of the attack is exhausted. gas warfare.—though all civilised nations have condemned the use of poison gas in warfare, it is considered necessary to take measures for defence against it. the chemical composition of poison gases is described under chemical warfare; we are here concerned with their tactical employment. poison gas may be lethal or disabling; phosgene is an instance of the deadly kind, while mustard gas and lachrymatory gas are not fatal. chlorine is disabling and ultimately fatal. further, these gases may be so volatile as to disappear in a few minutes, or they may impregnate the ground so that the effect lasts for weeks. these are known as non-persistent and persistent forms of gas. troops may be protected from breathing gas by gas-masks and respirators, but these cannot be worn indefinitely; men must remove them to eat and sleep. it is impossible to protect them from mustard gas, which causes painful burns on the hands and legs. mustard gas is persistent; a wood or a village impregnated with it will remain impossible to enter for weeks. phosgene is comparatively volatile, and a light breeze is sufficient to dis- sipate it; chlorine is a heavy gas, and may remain in trenches and hollows for many hours if there 1s no wind. poison gas may be discharged from cylinders, and carried by the wind towards the enemy, or it may be discharged by gas projectors, which are special mortars throwing a 60-lb. drum containing gas-generating liquid; or gas shells may be fired by ordinary artillery, usually light and medium howitzers. gas shells require a special range table, as they are lighter than ordinary shell. they are fired either entirely by map, or after preliminary ranging with ordinary shell, as their impact cannot be observed. hot sunshine causes volatile gas to dis- perse quickly, and a strong wind blows it away; gas is therefore most effective on a cloudy, still day. the shells are pitched to windward of the target so that the breeze will carry the gas in the required direction. in this respect guns are more efficient than gas cylinders, as they are not obliged to await the coming of a favourable wind. gas bombardments are used for various purposes. thus a piece of ground soaked with persistent gas is denied to the enemy; batteries of artillery, especially when sited in hollows or woods, may be neutralised; trenches which are being attacked may be bombarded with non-persistent gas, which will have cleared away by the time the attacking infantry reach them. enclosed spaces, such as houses and dug-outs, are readily made untenable. troops wearing masks lose much of their fighting efficiency and even a small number of gas shells may induce the enemy to put on their gas-masks, and so reduce their fire-effect. the number of gas shells required for an effective bombard- ment varies according to the weather, the calibre of the piece, and the nature of the gas used. with the light ficld howitzer of to5-mm. (4:2-in.) calibre, in fairly still weather, it is reckoned that one round per metre of front is required with non-persistent gas, or two rounds with persistent gas. these figures include only the shells which pitch in the target or within 50 metres to windward of it. see ammunition; ballistics; explosives; ordnance; for naval guns see gunnery, naval. bibliography—f. marre, notre “75” (1915); d. a. macalister, field gunnery (1917); c. nordmann, a coups de canon (1917); art sales general f. e. gasconin, evolution de l’artillerie pendant la guerre (1920); georg bruchmuller, die deutsche artillerie in den durch- bruchschlachten des weltkriegs (1921); e. gimmerle, affenlehre (1924). (h. a. b.)",
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