The question of finding working parties is, however, a minor consideration for the infantry when compared with the possible effects of the explosion of a German mine. This usually occurred either as darkness fell or during the night. Though warning might have been given by the tunnellers that a mine was to be expected, yet the explosion always appeared to come as a surprise. To a man standing up in the vicinity of an explosion the first sensation was a feeling that he had been struck on the soles of the feet by a heavy beam. This was immediately followed by the opening up of the earth and the issuing forth of a belch of flame, capped with a great rolling cloud of smoke and followed instantaneously by a deep muffled roar.
Huge fragments of earth and chalk, some weighing a ton or more, with wire entanglements, trench-boards, dug-out timbers—all were hurled many feet into the air. There followed a sensible pause, and then for some seconds the falling débris would come pouring down. This in turn was followed by a mist of dust which continued to float in the air for many minutes.
If the explosion had occurred under an occupied portion of the trench, the men in the area which was transferred into the crater were either immediately buried or else hurled many feet into the air in the sheet of flame and smoke, often to descend back into the crater crushed, bruised, burnt, and almost invariably dead. Others in the immediate vicinity of the explosion were crushed in their shelters or buried in the trenches by the collapse of their sides. Men further away, in their turn, were in danger of being killed or mutilated by the falling débris of stones and chalk which whirled down from a great height into the trenches. The result was a scene of horrible desolation. Nothing remained intact. Trenches with their garrisons were obliterated. The positions where posts had once been could only be determined by rifles or limbs projecting through the upturned earth. At times, the heaving of the earth showed where some buried man, still alive, was struggling to extricate himself. The whole air was fetid with the sickly stench of high explosive.
Mine warfare was, indeed, the most trying ordeal to which troops holding trenches were exposed.
Next to mining, the most nerve-racking form of trench warfare was provided by the trench-mortar. Towards the latter end of August the enemy began to make a considerable use of these weapons. In consequence the trenches were frequently severely damaged, and many casualties were sustained. The British trench-mortars were in these days only in their early experimental stages; moreover, difficulty always existed in obtaining sufficient ammunition for them to be of any real service.
The enemy, on the other hand, appears to have had an unlimited supply of ammunition for mortars of a considerably heavier calibre and longer range than ours. At this time his commonest types were those that discharged the “oil can” or “rum jar” and the aerial torpedo. The “oil can” was little more than a tin canister about nine inches in diameter, filled with high explosive, and fitted with a time fuze. In those days it was fired from a smooth-bored wooden mortar, and in consequence turned over and over in its flight, and was therefore not particularly accurate. The explosion was, however, terrific, devastating to wire or trenches, and most trying to the nerves of any one who had to live in an area in which they habitually burst.
The aerial torpedoes had a fixed propeller which kept them from turning over in the air, and were in consequence a more accurate projectile. Their effects were if anything worse than those of the “oil can.”
The Division had attached to it one 1½-inch mortar battery and a 4-inch mortar battery for which ammunition was available only in small quantities. On 2nd September, a 2-inch trench-mortar battery arrived, though its ammunition did not join it till 7th October.
The 2-inch trench-mortar fired a bomb exactly similar in shape to the hammer used in Highland games in “throwing the hammer.” For this reason it was known to the troops as “Donald Dinnie.” It was also known as the “Plum Pudding” or “Football.” It was on this account that an English brigade-major was once heard to confess that he had always thought “Donald Dinnie” was Scots for plum pudding.