“To enable the attack to be prosecuted it is clear that from this moment the hostile fire must be met by fire of greater power, _its intensity and duration being dependent on the effect produced_. Moreover, from this point forward movement will as a rule be contingent on the mutual fire support afforded to one another by neighbouring bodies, and on the effects produced by the _covering fire brought to bear on the enemy’s line_ wherever the ground admits of such action, by supports, reserves, and the troops specially told off for this purpose. Covering fire should be delivered so as to strike the enemy, disturb his aim, and compel him to seek shelter when the assailant is exposed or in difficulties. _In such circumstances intensity of fire is of the first importance; but fire should be reserved when the assailants’ progress is satisfactory, or when he is under cover._”[17] No one who has controlled the covering fire of infantry, even on manœuvres, will dispute the immense difficulty of timing the opening and ceasing of such a fire, with even a company, to coincide with the advance of the troops covered; while the necessity for observation of fire and its concentration on certain parts of the enemy’s position make it still more difficult effectively to cover the advance of troops with rifle fire at long range. That machine guns will be able to perform this duty far more effectively and easily than infantry is manifest from the nature of the fire required, the features being _intensity_, _control_, and _concentration_, all of which are characteristic of machine guns. When required to cover the advance of infantry, machine guns should be used in batteries and must be so placed that they are able to see the infantry they are covering, and to sweep those portions of the enemy’s position from which fire can be brought to bear on the advancing troops. If the enemy’s artillery is not silenced or at least dominated by that of the attackers, it will be necessary to conceal the machine guns from view and provide cover from fire. That machine guns well concealed and provided with cover (pits) are able to remain in action under artillery fire for considerable periods, is proved by instances in the Russo-Japanese War (see Chapter III. p. 28). Major Kuhn, who was with the Japanese Army in Manchuria, in his report states: “Importance is laid on concealing the guns, and it was claimed that none had been knocked out by the Russian artillery.” Covering fire from the flanks is more likely to be effective than frontal fire, because it will enfilade entrenchments, reach men behind natural cover and have a more disconcerting morale effect than frontal fire. It will not always be possible to find suitable fire positions on the flanks for machine guns at this stage of the attack, and it will then be necessary to place them in rear of the attacking infantry and fire over their heads. This can be done with perfect safety--indeed,