er-attacks at Cambrai (November 30-December 4, 1917)
_Tanks_ were effectively employed in wood and village fighting, and
were in a great measure responsible for the capture of _Gauche Wood_,
acting in co-operation with dismounted Indian cavalry of the 5th
Cavalry Division and with the Guards' Division; but although they
reached the outskirts of _Villers Guislain_ they were forced to
withdraw, as the supporting infantry were unable to co-operate owing to
the fire of the enemy's machine guns. At the _Battle of Messines_
(June 7, 1917) a tank enabled the infantry to proceed with the advance
by overcoming the machine guns posted in Fanny's Farm. Generally
speaking, however, tanks are unable to manoeuvre in woods, owing to the
many insuperable obstructions, and their sphere of usefulness is
limited by the availability of rides or other cleared avenues of
approach. During the fighting for the interior of the wood
"reconnaissance during battle" is of the highest importance, and the
flanks of the attacking force will need to be specially guarded, on
account of the liability to counter-attack. Touch must also be kept,
to avoid loss of direction. In the _advance from the captured
position_ great tactical skill is required, and if the defenders have
established a fire position within close range it may only be possible
to issue from the wood when co-operating troops have cleared or
neutralised that position. It may even be necessary to hold the rear
edge against counter-attack and to debouch, after reorganisation, from
both flanks or from the opposite edge, to advance in two bodies against
the flanks of the fire position under harassing fire from the troops in
the further edge. If the fire position is to be carried by direct
assault, or if {161} it can be got under control and the advance is to
be continued, the successful troops must be reorganised within the wood
(care being taken to avoid concentration in salients) and must deploy
before advancing, to bound forward in one rush until clear of the wood.

DEFENCE OF A WOOD.--The outer edge of a wood is particularly
vulnerable, but some portions of it must of necessity be occupied for
purposes of observation and resistance (particularly at night), while
the unoccupied portions are heavily entangled and made subject to
enfilade fire from the occupied positions, machine and Lewis guns being
particularly suitable for the defensive positions, in concealed and
strengthened emplac