multiplicity of the weapons used, their functions and their limitations.
The "three arms"--a term universally applied to infantry (q.v.), cavalry
(q.v.) and artillery (q.v.)--coexist owing to the fact that each can
undertake functions which the others cannot properly fulfil. Thus
cavalry can close with an enemy at the quickest pace, infantry can work
in difficult ground, and artillery is effective at great ranges.
Infantry indeed, having the power of engaging both at close quarters and
at a distance, constitutes the chief part of a fighting force. Other
"arms," such as mounted infantry, cyclists, engineers, &c., are again
differentiated from the three chief arms by their proper functions. In
deciding upon the establishment in peace, or the composition of a force
for war, it is therefore necessary to settle beforehand the relative
importance of these functions in carrying out the work in hand. Thus an
army operating in Essex would be unusually strong in infantry, one on
Salisbury Plain would possess a great number of guns, and an army
operating on the South African veldt would consist very largely of
mounted men. The normal European war has, however, naturally been taken
as the basis upon which the relative proportions of the three arms are
calculated. At the battle of Kolin (1757) the cavalry was more than half
as strong as the infantry engaged. At Borodino (1812) there were 39
cavalry to 100 of other arms, and 5 guns per 1000 men. In 1870 the
Germans had at the outset 7 cavalrymen to every 100 men of other arms,
the French 10. As for guns, the German artillery had 3, the French 3-1/2
per 1000 men. In more modern times the proportions have undergone some
alteration, the artillery having been increased, and the cavalry brought
nearer to the Napoleonic standard. Thus the relative proportions, in
peace time, now stand at 5 or 6 guns per 1000 men, and 16 cavalry
soldiers to 100 men of other arms. It must be borne in mind that cavalry
and artillery are maintained in peace at a higher effective than
infantry, the strength of the latter being much inflated in war, while
cavalry and artillery are not easily extemporized. Thus in the
Manchurian campaign these proportions were very different. The Russian
army on the eve of the battle of Mukden (20th of February 1905)
consisted of 370 battalions, 142 squadrons and 153 field batteries (1200
guns), with, in addition, over 200 heavy guns. The strength of this
force, which was organized in three armies, was about 300,000 infantry
and 18,000 cavalry and Cossacks, with 3-1/2 guns per 1000 men of other
arms. The Japanese armies consisted of 300,000 infantry, 11,000 cavalry,
900 field and 170 heavy guns, the proportion of field artillery being
2-1/2 guns per 1000 men.
It is perhaps not superfluous to mention that all the smaller units in a
modern army consist of one arm only. Formerly several dissimilar weapons
were combined in the same unit. The knight with his four or five
variously armed retainers constituted an example of this method of
organization, which slowly died out as weapons became more uniform and
their functions better defined.