The French have very quickly organised the hooter system. Some one says that a look-out at the lines, on seeing the flash of the gun, presses a button which rings a bell in Dunkerque. The signal is sent on to the man in the light-ship at the docks, and he pulls the string of his syren. The complete operation only takes some ten or twelve seconds, and as the shell is travelling for well over a minute it gave ample warning. As a matter of fact, such a system, if it does exist, is not necessary, as the shells are falling at an exact interval of just over seven minutes. The order is now given by the C.O. for work to be abandoned, and for the men to take cover. With one of the pilots I make a tour of the neighbourhood, examining the shell-holes in the surrounding fields. The columns of earth and smoke shoot up at regular intervals some half a mile away, and we do not trouble much about them. I return to the aerodrome and, meeting another friend, walk back across the field. A whistle is blown. "That's old Charlie!" he says. "He's sitting in the canal with a stop-watch and a whistle. The C.O. put him on to it. Let's sit down till it has gone off!" I suggest going on, as we are just as safe anywhere. He sits down on the edge of a small patch of growing corn; I sit beside him. Suddenly, while we are arguing whether we should go on or not, I seem to see something through the back of my head. I look quickly round, and there, towering some eighty or ninety feet high, only a few yards from us, is a tall fountain of black earth and uprising smoke, like the great genie which whirled upwards from the bottle in the fairy story. "A shell--lie down!" I yell, and throw myself face forwards on the ground with my hands over the back of my head. In the moments of waiting before anything happens, I realise that I cannot be killed by the actual explosion of this shell although it is so near, as I have lived to see it, and then ... thump, thump, on my arms, my back, and my legs the pieces of earth begin to beat. They are heavy and, since they are dropping from some fifty feet or more, are very painful. The dust and stones rain down all over me and all round. I can hear the returning earth thundering on the ground. Faster and faster come the blows upon me; it is very much like being caned, and I know that at any moment a heavy piece of metal may drop and crush my skull. I cannot get up and run; I am in some way hypnotised. Beside me I am conscious of my friend cowering close against the ground as well. For seeming hours the hail of missiles continues, and I receive some very severe blows. At last it ceases. We scramble to our feet and begin to run away through the smoke, and then the eternal instinct grips us. We turn, and run back to get souvenirs from the crater. The size of it staggers us. It is almost big enough to put a motor omnibus in ... and the place where we were sitting is only a few feet away from the edge of the hole.