THE PLACE OF SIGNALLING IN WAR Its older forms, which are prehistoric, must be numbered among those savage arts that civilization kills but cannot emulate, of which the mysterious passage of news through the African bush is an example to this day. Compared with them the famous beacon fires, calling England to arms as the Armada sailed up channel, were crude enough. The semaphore stations, each with its tall mast and signalling arms, which linked London with the south coast while Napoleon's Grand Army waited at Boulogne, were an advance, for they could spell out any message—they have given its name to more than one Telegraph hill in the south of England. In the early 19th century also, Sir Home Popham intro duced the system of flag hoists in the British navy. But it is only with the help of applied science that civilized man has lately learnt to communicate with his fellows at a distance, by means of the "electric telegraph" of the mid-nineteenth century, to be followed two generations later by wireless telegraphy.
In spite of our evidence of man's need from early times to com municate afar, on the field of battle for countless years we see little sign of any attempt at control by signal. "Horns are heard blowing in the mist, and a confused uproar of savage tumult and outrage." Kings and captains, themselves in the thick of the press, were content to command by voice and example. It is not that the need was never felt; we learn in the Song of Roland how Charles the Great, as he marched north out of Spain, heard his lieutenant's horn blown for help in the mountains behind him; how he heard the signal twice and misread it, grasped its meaning the third time and turned back too late to save his rearguard. For one such incident made immortal in verse there must have been many lost in obscurity. None the less, through ages of warfare, the means of control in battle were more or less adequate to the needs. Firearms came and the long bow disappeared; modern nations appeared in arms, first the French and then the Germans, and tens of thousands co-operated on the battlefield in an iron discipline. Yet troops still fought in close order; generals con
tinued to command from the saddle ; the word of command, trum pet and bugle call and the galloping staff officer gave to corn manders all the control they needed. The duke of Wellington could say at Waterloo, "The whole line will advance," and could watch the squares swing into line as his order took effect.
Then came the industrial revolution which was to affect war no less than every other branch of human activity, and in half a century all was changed. In 1861 the beginning of the American Civil War saw the old order but little altered; the technique of war remained comparatively simple and dealt in the traditional elements of horse, foot and smooth-bore artillery. In 1918 the end of the World War saw armies so vast and so complex in arma ment that the most elaborate signal systems scarcely sufficed for their control. The process continues apace. In the second decade after the war we find a commander still disposing of infantry, artillery and cavalry, it is true ; but half the infantry is armed with machine guns or automatic rifles; the gunner rarely sees his enemy; cavalry carry machine guns and must co-operate with mechanized fire units to retain their power of movement. The three older arms are altered beyond recognition, and in addition a commander has tanks, armoured cars and aircraft. These ele ments, widely deployed under the enemy's fire, he must weld into a single living organism, driven by one brain and working to one end. The problem of signalling is to enable a commander to achieve this ideal, and all his powers of fire and movement avail him only in so far as the problem is solved. Moreover, he must see before he can strike. All commanders grope in the fog of war, and the extent to which that fog may thin from time to time or allow a precious clear glimpse depends very much upon the state of signal communication. In addition, the infinite material needs of a modern army make as great demands upon intercommunica tion as does the actual conduct of battle.