The audacity of the adventure lay in the poverty of manpower with which it was attempted and supported. The divisions engaged had all been through the grinding mill of Flanders and were tired men. The artillery was made up largely of those batteries which had been axle-deep in Flanders mud. It was clearly understood by General Byng and Gen. Louis Vaughan, his chief of staff, that Sir Douglas Haig could not afford to give them strong reserves to exploit any success they might gain by surprise or to defend the captured ground against certain counterattacks. It was to be a surprise assault by tanks and infantry, with the hope that the cavalry corps might find its gap at last and sweep round Cambrai before the enemy could recover and reorganize. With other correspondents I saw Gen. Louis Vaughan, who expounded the scheme before it was launched. That charming man, with his professional manner, sweetness of speech, gentleness of voice and gesture, like an Oxford don analyzing the war correspondence of Xenophon, made no secret of the economy with which the operation would have to be made.