Then there is Unter den Linden. This celebrated thoroughfare is an old communication-trench. It runs, half-ruined, from the old German trench in our rear, right through our own front line, to the present German trenches. It constitutes such a bogey as the Channel Tunnel scheme once was: each side sits jealously at its own end, anticipating hostile enterprises from the other. It is also the residence of "Minnie." But we will return to Minnie later. The artillery of both sides, too, contributes its mite. There is a dull roar far in the rear of the German trenches, followed by a whirring squeak overhead. Then comes an earth-shaking crash a mile behind us. We whip round, and there, in the failing evening light, against the sunset, there springs up the silhouette of a mighty tree in full foliage. Presently the silhouette disperses, drifts away, and---- "The coals is hame, right enough!" comments Private Tosh. Instantly our guns reply, and we become the humble spectators of an artillery duel. Of course, if the enemy gets tired of "searching" the countryside for our guns and takes to "searching" our trenches instead, we lose all interest in the proceedings, and retire to our dugouts, hoping that no direct hits will come our way. But guns are notoriously erratic in their time-tables, and fickle in their attentions. It is upon Zacchæus and Unter den Linden--including Minnie--that we mainly rely for excitement. III--STORY OF AYLING OF THE MACHINE GUNNERS As already recorded, we took over these trenches a few days ago, in the small hours of the morning. In the ordinary course of events, relieving parties are usually able to march up under cover of darkness to the reserve trench, half a mile in rear of the firing line, and so proceed to their appointed place. But on this occasion the German artillery happened to be "distributing coal" among the billets behind. This made it necessary to approach our new home by tortuous ways, and to take to subterranean courses at a very early stage of the journey. For more than two hours we toiled along a trench just wide enough to permit a man to wear his equipment, sometimes bent double to avoid the bullets of snipers, sometimes knee-deep in glutinous mud. Ayling, leading a machine-gun section who were burdened with their weapons and seven thousand rounds of ammunition, mopped his steaming brow and inquired of his guide how much farther there was to go. "Abart two miles, sir," replied the youth with gloomy satisfaction. He was a private of the Cockney regiment whom we were relieving; and after the manner of his kind, would infinitely have preferred to conduct us down half a mile of a shell-swept road, leading straight to the heart of things, than waste time upon an uninteresting but safe _détour_. At this Ayling's Number One, who was carrying a machine-gun tripod weighing forty-eight pounds, said something--something distressingly audible--and groaned deeply.