On our left an encampment of Nissen huts—­so called from their inventor, a Canadian officer—­those new and ingenious devices for housing troops, or labour battalions, or coloured workers, at an astonishing saving both of time and material.  In shape like the old-fashioned beehive, each hut can be put up by four or six men in a few hours.  Everything is, of course, standardised, and the wood which lines their corrugated iron is put together in the simplest and quickest ways, ways easily suggested, no doubt, to the Canadian mind, familiar with “shacks” and lumber camps.  We shall come across them everywhere along the front.  But on this first occasion my attention is soon distracted from them, for as we turn a corner beyond the hut settlement, which I am told is that of a machine-gun detachment, there is an exclamation from D——.

Tanks!  The officer in front points smiling to a field just ahead.  There is one of them—­the monster!—­taking its morning exercise; practising up and down the high and almost perpendicular banks by which another huge field is divided.  The motor slackens, and we watch the creature slowly attack a high bank, land complacently on the top, and then—­an officer walking beside it to direct its movements—­balance a moment on the edge of another bank equally high, a short distance away.  There it is!—­down!—­not flopping or falling, but all in the way of business, gliding unperturbed.  London is full of tanks, of course—­on the films.  But somehow to be watching a real one, under the French sky, not twenty miles from the line, is a different thing.  We fall into an eager discussion with Captain F. in front, as to the part played by them in the Somme battle, and as to what the Germans may be preparing in reply to them.  And while we talk, my eye is caught by something on the sky-line, just above the tank.  It is a man and a plough—­a plough that might have come out of the Odyssey—­the oldest, simplest type.  So are the ages interwoven; and one may safely guess that the plough—­that very type!—­will outlast many generations of tanks.  But, for the moment, the tanks are in the limelight, and it is luck that we should have come upon them so soon, for one may motor many miles about the front without meeting with any signs of them.

Next, a fine main road and an old town, seething with all the stir of war.  We come upon a crowded market-place, and two huge convoys passing each other in the narrow street beyond—­one, an ammunition column, into which our motor humbly fits itself as best it can, by order of the officer in charge of the column, and the other, a long string of magnificent lorries belonging to the Flying Corps, which defiles past us on the left.  The inhabitants of the town, old men, women and children, stand to watch the hubbub, with amused friendly faces.  On we go, for a time, in the middle of the convoy.  The great motor lorries filled with ammunition hem us in till the town is through, and a long hill is climbed.  At the top