Presently we arrive at PICCADILLY CIRCUS, a muddy excavation in the earth, from which several passages branch. These thoroughfares are not all labelled with strict regard for London geography. We note THE HAYMARKET, also PICCADILLY; but ARTILLERY LANE seems out of place, somehow. On the site, too, of the Criterion, we observe a subterranean cavern containing three recumbent figures, snoring lustily. This bears the sign CYCLISTS' REST. We, however, take the turning marked SHAFTESBURY AVENUE, and after passing (quite wrongly, don't you think?) through TRAFALGAR SQUARE--six feet by eight--find ourselves in the actual firing trench. It is an unexpectedly spacious place. We, who have spent the winter constructing slits in the ground two feet wide, feel quite lost in this roomy thoroughfare. For a thoroughfare it is, with little toy houses on either side. They are hewn out of the solid earth, lined with planks, painted, furnished, and decorated. These are, so to speak, permanent trenches, which have been occupied for more than six months. Observe this eligible residence on your left. It has a little door, nearly six feet high, and a real glass window, with a little curtain. Inside, there is a bunk, six feet long, together with an ingenious folding washhand-stand, of the nautical variety, and a flap-table. The walls, which are painted pale green, are decorated with elegant extracts from the "Sketch" and "La Vie Parisienne." Outside, the name of the villa is painted up. It is in Welsh--that notorious railway station in Anglesey which runs to thirty-three syllables or so--and extends from one end of the façade to the other. A small placard announces that Hawkers, Organs, and Street-cries are prohibited. "This is my shanty," explains a machine-gun officer standing by. "It was built by a Welsh Fusilier, who has since moved on. He was here all winter, and made everything himself, including the washhand-stand. Some carpenter--what? of course I am not here continuously. We have six days in the trenches and six out; so I take turns with a man in the Midland Mudcrushers, who take turns with us. Come in and have some tea." It is only ten o'clock in the morning, but tea--strong and sweet, with condensed milk--is instantly forthcoming. Refreshed by this, and a slice of cake, we proceed upon our excursion. The trench is full of men, mostly asleep; for the night cometh, when no man may sleep. They lie in low-roofed rectangular caves, like the interior of great cucumber-frames, lined with planks and supported by props. The cave is really a homogeneous affair, for it is constructed in the R.E. workshops and then brought bodily to the trenches and fitted into its appointed excavation. Each cave holds three men. They lie side by side, like three dogs in a triple kennel, with their heads outward and easily accessible to the individual who performs the functions of "knocker-up."