Even then they might be deadly with magazine fire at close quarters. Save for their liability to such attacks, a few hundreds of such men could hold positions of a quite vast extent, and a few thousand might hold a frontier. Assuredly a mere handful of such men could stop the most multitudinous attack or cover the most disorderly retreat in the world, and even when some ingenious, daring, and lucky night assault had at last ejected them from a position, dawn would simply restore to them the prospect of reconstituting in new positions their enormous advantage of defence. The only really effective and final defeat such an attenuated force of marksmen could sustain, would be from the slow and circumspect advance upon it of a similar force of superior marksmen, creeping forward under cover of night or of smoke-shells and fire, digging pits during the snatches of cessation obtained in this way, and so coming nearer and nearer and getting a completer and completer mastery of the defender's ground until the approach of the defender's reliefs, food, and fresh ammunition ceased to be possible. Thereupon there would be nothing for it but either surrender or a bolt in the night to positions in the rear, a bolt that might be hotly followed if it were deferred too late. Probably between contiguous nations that have mastered the art of war, instead of the pouring clouds of cavalry of the old dispensation,[37] this will be the opening phase of the struggle, a vast duel all along the frontier between groups of skilled marksmen, continually being relieved and refreshed from the rear. For a time quite possibly there will be no definite army here or there, there will be no controllable battle, there will be no Great General in the field at all. But somewhere far in the rear the central organizer will sit at the telephonic centre of his vast front, and he will strengthen here and feed there and watch, watch perpetually the pressure, the incessant remorseless pressure that is seeking to wear down his countervailing thrust. Behind the thin firing line that is actually engaged, the country for many miles will be rapidly cleared and devoted to the business of war, big machines will be at work making second, third, and fourth lines of trenches that may be needed if presently the firing line is forced back, spreading out transverse paths for the swift lateral movement of the cyclists who will be in perpetual alertness to relieve sudden local pressures, and all along those great motor roads our first "Anticipations" sketched, there will be a vast and rapid shifting to and fro of big and very long range guns. These guns will probably be fought with the help of balloons. The latter will hang above the firing line all along the front, incessantly ascending and withdrawn; they will be continually determining the distribution of the antagonist's forces, directing the fire of continually shifting great guns upon the apparatus