So we ate and listened to the singing, while the moon rose, and with it came a fog—­more than a fog—­a cloud of heavy mist that hid the moon.  We moved our baggage from the tent to a vacant room in a vacant ward in the big hospital.  We saw in the misty moonlight a great brick structure running around a compound.  The compound was over 200 feet square, and in the centre of the compound was a big Red Cross made of canvas, painted red, on a background of whitewashed stones.  It was 100 feet square.  On each side of the compound a Red Cross blazed from the roof of the buildings, under the Geneva lights—­lights which the Germans had agreed should mark our hospitals and protect them from air raids.

At midnight we left the hospital to visit those ambulance men who were stationed at the first aid posts, up near the battle line.  It was an eery sort of night ride in the ambulance, going without lights, up the zigzags of the hill to the battle front of Verdun.  The white clay of the road was sloppy and the car wobbled and skidded along and we passed scores of other vehicles going up and coming down—­with not a flicker of light on any of them.  The Red Cross on our ambulance gave us the right of way over everything but ammunition trucks, so we sped forward rapidly.  It was revitalment time.  Hundreds of motor trucks and horsecarts laden with munitions, food, men and the thousand and one supplies needed to keep an army going, were making their nightly trip to the trenches.  When we reached a point near the top of the long hill, which we had been climbing, we got out of the ambulance and found that we were at a first aid dugout just back of the hill from whose top one could see the battle.  The first aid post was a cave tunnelled a few yards into the hillside covered with railroad iron and sandbags.  In the dugout was a little operating room where the wounded were bandaged before starting them down the hill in the ambulance to the hospital, and three doctors and half a dozen stretcher bearers were standing inside out of the misty rain.

As we had been climbing the hill in the ambulance, the roar of the big guns grew louder and louder.  We believed it was French cannon.  But when we got out of the car we heard an angry whistle and a roar which told us that German shells were coming in near us.  As we stood before the dugout shivering in the mist we saw beyond us, over the hill, the glare of the French trench rockets lighting up the clouds above us weirdly, and spreading a sickly glow over the white muddy road before us.  On the road skirting the very door of the dugout passed a line of motor trucks and carts—­the revitalment train.  The mist walled us in.  Every few seconds out of the mist came a huge grey truck or a lumbering two-wheeled cart; and then, creaking heavily past the dugout door, plunged into the mist again.  Never did the procession stop.  At regular intervals the German shells crashed into the woods farther up the hill beyond us.