And so it was that it was our fate up to the first Cambrai battle to “chip in when we could” in conditions entirely unfavourable. The employment of Tanks in Flanders has often been criticised, without intelligent appreciation of the fact that had they not fought in Flanders they would have probably fought nowhere. Better, therefore, that they should fight and pull less than half their weight, and still save lives, than that they should stand idle while tremendous issues were at stake. * * * * * If employment in the field was a struggle between policy and expediency, the principles of production and design represented a direct conflict of opposing policies, resulting happily in compromise. The fighting man, conscious of the weaknesses of the earlier weapons, and visualising development which he believed to be obtainable, and knew to be necessary, and the soldier-engineer overburdened with difficulties of maintenance and cursed with the nightmare of Spares and Spares and more Spares--both cried aloud from France for rapid progress in design. In England the other side of the picture was presented with equal force. The process of bulk production necessitates orders placed long in advance, materials were difficult to obtain, plans of track work and workshop organisation are not susceptible of change without delay, change, too, entailing irritation of factory staffs and workmen. Production once agreed to and embarked upon, a very complicated machinery is with difficulty set in motion. To stop or change this machinery results often in a loss of output which is in no way compensated by the improvements ultimately obtained. The same problem must have occurred in many branches of war production. The best, however, is only the enemy of the good, if the good is good enough. You have portrayed the difficulties arising from these conditions in Chapter V. The picture you draw belongs to the earlier stages, when the two sides worked rather upon regulation than upon formula. The later stages of the war saw a very full appreciation of each other’s point of view and the growth of a very sturdy spirit of co-operation, which carried us over more than one difficulty to meet which special appliances or special construction were necessary. * * * * * The Tank, as a weapon, has been threatened with several crises. Some have been averted by intelligent forecast in specification. Some have been dealt with by the improvisations of the engineers both in France and in England. Some have disappeared before a general improvement in design. You, I think, have touched on one crisis only--the mud crisis. The mud crisis was defeated at long last, but the swamp crisis, never. Although none of the other troubles was of long duration, any one of them, unless cured, would have caused a permanent disappearance of the arm.