_Field Service Regulations_, 1909, speaking of rear guards in mountain warfare, says: “Mountain artillery should usually form part of a rear guard, _and machine guns may be usefully employed_. The withdrawal of the artillery is usually an encouragement to the enemy to press on, and on such occasions machine guns will often find scope for action....” “If the rear-guard commander considers it impossible to reach camp before nightfall, it will generally be advisable for him to halt and bivouac for the night in the most favourable position for defence.” Here, again, machine guns will be most useful in defending the bivouac after dark if trained by daylight to sweep approaches, while the morale effect of its accurate fire in the dark will be considerable. There are many instances from our wars on the North-West Frontier where machine guns might have been used profitably in covering the retreat; but to be successfully employed in such cases, they must be far more mobile and better trained for rapid-fire practice than they have been in the past. Lieut.-Colonel Haughton’s retreat from the Iseri Kandeo Pass is typical of such operations. “A brigade had been sent on detached duty into the Warais Valley, and after completing its work there was rejoining the rest of the army in Maidan. In doing so the brigade had to cross the Iseri Kandeo Pass over the hills which separate the two valleys. As the force quitted its bivouacs the Ghurkas were left as rear guard, while the 15th Sikhs were told off to hold the Kotal, which was about half-way. The main body and baggage moved off early, and the latter reached the maidan almost unnoticed. The Ghurkas, however, were pressed from the commencement of the retirement right up to the top of the Kotal; then they marched on, leaving the 15th Sikhs to cover the retirement. As the Sikhs began to draw in their piquets from the heights above the pass, the Afridis, as was their wont, grew bolder and bolder, and, taking advantage of the cover of a wood hard by, they crept down close to the rear guard. One company as it withdrew was suddenly charged by a crowd of swordsmen.... But those who participated in this rush paid dearly for their temerity, the Sikh company meeting them with steady musketry and being most opportunely reinforced by another company. The carrying off of the wounded was, however, becoming a matter of serious difficulty, so reinforcements were asked for. These arrived in the shape of two companies of Dorsets and of several companies of the 36th Sikhs under Lieut.-Colonel Haughton, who assumed command, and who withdrew his force down the hill without much loss.”[59] It is easy to imagine how machine guns might have been used here, and how their presence might even have rendered the reinforcements unnecessary; but unless they are capable of coming into action and opening fire in thirty seconds, and of packing up and moving off again after ceasing fire in the