be fired along a straight thirty yards of trench, if the Germans ever got in. But to fire a rifle to any purpose the loop-hole must not be broken, and so the Sapper made a note before resuming his stroll.
Rounding a bend, a big white board at a crossroads confronted him. It advertised two or three salient facts written in large black letters. It appeared that by turning to the right one would ultimately reach Leicester Square and an aid post, to say nothing of the Charing Cross Road, which was a down trench. By turning to the left, on the contrary, one would reach Regent Street and a pump. It also stated that the name of our wanderer's present route was the Haymarket, and further affirmed that it was an up trench. For it will be plain to all that, where a trench is but three feet wide, it is essential not to have men going both ways in it—and further, it will also be plain why the aid posts occur in the down ones.
A further interesting and momentous piece of information was imparted from another board, to the effect that the name of the trench by which one could reach the pump on one hand and the aid post on the other was Piccadilly, and that it constituted the reserve line of the position.
In other words, it was not merely a communication trench, but was recessed and traversed like a fire trench. In very fact, it was a fire trench—the third of the system. In front was the support line, known as Pall Mall, and in front of that, again, the firing line, whither later the Sapper proposed to wend his
