personnel and absorbed any surplus regular reservists and sick
and immature men of the mobilized regular units. In addition
to the manning of the coast defences, certain vulnerable points
e.g. possible landing-places for small raiding-parties, cable
landing stations, wireless receiving stations, vital railway bridges
required watching or protection at the inception of the
precautionary period. This was undertaken as an additional
obligation by the special service sections of the Territorial Force,
each being allotted a particular war station. Those units of the
Territorial Force not absorbed either at once or after relief by
the special reserve units in coast defences, were assembled for
training in their infantry divisions and mounted brigades;' and
preparations were completed for their rapid conveyance to any
threatened point.
In actual fact a slight variation from the original scheme was made for a few days in respect of the disposition of the 4th Reg- ular Division of the Expeditionary Force. This division, whose normal peace stations were in Woolwich, Shorncliffe, Dover, Chatham and Colchester, was ordered on the third day of mobil- ization to send small forces of infantry and artillery to Norfolk, Yorkshire and Edinburgh. Its headquarters were later moved to Bury St. Edmunds, and took over for some days the command of the east coast (excluding coast defences), until a Territorial mounted division was sufficiently organized to release the 4th Division for the Expeditionary Force in France. Similarly, the 6th Division from Ireland was brought over to England and assembled as a support to the Territorial formations guarding the east coast. This division, an integral part of the Expedi- tionary Force, was retained at home for this defensive purpose until the beginning of Sept. and only then followed the Expedi- tionary Force, joining it on the Aisne. General mobilization was, therefore, really confined to the regular units comprising the Expeditionary Force.
To deal first with personnel. As a constant preparation for mobilization, each unit during peace compiled twice yearly a mobilization form, showing the personnel actually available with the unit, less those required for duty elsewhere and those immature or insufficiently trained for the field. This form was passed to the record office concerned, which, after stating the number of reservists detailed for the unit and its first reinforcements (which invariably accompany it overseas), and any deficiency or surplus of reservists, passed on the form to the War Office for investigation and informa- tion. The only action taken in the War Office was to detail the requisite number of officers from the reserve of officers and special reserve. The proclamation of mobilization and simultaneous issue of posters and individual notices summoned all reservists to rejoin the Colours -those of cavalry and artillery to allotted depots; those of infantry to regimental depots, where they were clothed, armed, equipped and dispatched as required to units, the residue remaining at depots for incorporation in special reserve units in course of embodiment. Those of other arms rejoined their units direct, there to be clothed, armed and equipped ; any surplus or deficiency being adjusted by their corps depots, where the surplus unallotted reservists rejoined. As regards materiel, each unit of the Regular Expeditionary Force (with the exception of certain mechan- ical transport units of the Army Service Corps) possessed the mobilization vehicles, arms and equipment required to pass from peace to war scale; and it was merely a question of issue and taking into use. As regards horses, the whole system had under- gone revision only just in time for actual mobilization. This system was that commands made a classified census of suitable horses available among the civil population. Any surplus over and above that required by units mobilizing in one command was re-allotted by the War Office to meet deficiencies in other com- mands e.g. the Aldershot command, which has practically no territorial area, obtained most of its horses from the London district, which mobilized very few troops. The system involved sending for the horses, but the loyal cooperation of inhabitants in voluntarily bringing their horses to named centres to a certain extent overcame this defect. Certain large firms had for some years received annual subsidies under a contract to provide on emergency a given number of horses of specified classes suited to military requirements.
The War Period. Owing to the special conditions of warfare which prevailed from 1914 onwards, to the progress of inventions, and to the variety of theatres in which operations took place, the standard organization of the original Expeditionary Force proved inadequate to meet the various requirements. It is, however, noteworthy that the structure of the infantry divi-
sion the main basis of organization remained substantially intact, though the strengths and the proportions of arms and services underwent modification, according to changing condi- tions and the special needs of certain theatres. Thus, to the divisional organization were added, for example, an employ- ment company and a salvage section.
Royal Engineers. In the later stages of the war the need in connexion with artillery-ranging for more accurate ground sur- veying than was afforded by the field-maps became evident. The three field survey companies employed prior to mobilization by the Board of Agriculture and Fisheries on the continuous survey of the United Kingdom were therefore expanded into field survey battalions, France receiving one per army and other theatres a due proportion. These included specialist sections termed topo- graphical, map, observation, sound-ranging and meteorological.
When mine warfare was added to trench warfare above ground, 25 special " tunnelling companies," recruited from coal-miners, were formed, each with an establishment of 14 officers and 307 other ranks. This was later raised, in the case of all but 5 companies, by 4 officers and 223 other ranks per company, by the attachment of infantry working parties.
Artisan works companies to the number of five were formed in France for the construction of hutting and other engineering work. Eleven forestry units, for the purpose of obtaining timber in France, were raised, and in addition a considerable number formed in Canada were employed in France, Scotland and Wales. Seven army tramway and foreway companies were formed in France to con- struct, maintain and operate trench tramways and light railways, and these eventually became transportation (R.E.) units. A " special works " unit (Camouflage Park) was formed in 1916 and operated throughout the armies. A small inundation section was formed in France in 1918.
Chemical Warfare. After the German gas attack at Ypres in April 1915 a start was at once made to select, organize and train the personnel who were to be concerned with the use of this new lethal weapon. The first special company of the Royal Engineers was formed for the purpose in July 1915, and numbered 186, and three other companies were in existence by Sept. of that year, taking part in the battle of Loos. Rapid progress continued ; during the winter 1915-6 the 4-in. Stokes mortar and an improved flame-thrower were developed, and in Oct. the special companies were expanded into a special brigade R.E., which was composed of a special (cylinder) company R.E., with an establishment of 8 officers and 250 other ranks, a special (mortar) company R.E., of 18 officers and 310 other ranks, and special sections R.E. (for flame-throwers) which, however, were never fully equipped or up to strength, the use of this weapon being soon abandoned. During 1917 this organization was again revised, and each of the five armies then in existence in France was provided with a headquarters special company R.E.- the various technical companies being allotted as required by the tactical situation.
The above was the organization for offensive action. Defensive measures against gas were first organized by the director-general of the army medical services; and in June and July of 1915 specialist officers were appointed to the headquarters of each army, where anti-gas schools were established. These officers were at first called " chemical officers," then " gas officers," and finally " chemical advisers." In March 1916 the defensive measures were taken over by the director of gas services for coordination with the offensive measures, and gas officers were appointed to all divisional head- quarters where anti-gas schools were established. The special brigade R.E. also provided non-commissioned officers to infantry brigades for the purpose of checking the fitness or otherwise of the respirators and for supervising the general state of gas defence. In March 1917, chemical advisers were appointed to each corps head- quarters. The gas services eventually expanded to a total of 490 officers and 6,875 other ranks.
Royal Artillery. In the original Expeditionary Force the ratio of guns to infantry was approximately 6 per 1,000 rifles, but as the war progressed so did gun-power show a marked increase; and whereas in Aug. 1914 Royal Artillery personnel throughout the world totalled 92,920, by Aug. 1918 it had reached 548,780. Taken in detail the horse artillery made but slight increase, the number of batteries rising from 26 to a maximum of 28 in 1918; field artillery increased from 153 to a maximum of 722 batteries in 1915. This number, however, was subsequently reduced to just over 600 6-gun batteries by the assimilation of a certain number of 4-gun batteries. A considerable reorganization took place later when the field artillery brigades were reclassed as " divisional " and " army." In the Royal Garrison Artillery, which manned the medium and heavy guns and howitzers as well as the few mountain batteries, the number of heavy batteries rose from 12 to a maximum of 100 in 1916; siege batteries from 3 to a maximum of 425 in 1917; mountain batteries from 9 to a maximum of 17 in 1918. Anti-aircraft sections, non-existent in 1914, reached a maximum of 275 in 1918. Trench mortar batteries, first formed in 1916, reached their maximum of 142 in 1917.
Machine-Gun Corps. In the autumn of 1915 the formation of the Machine-Gun Corps was decided upon. Originally consisting in
