"Horse artillery and machine-guns are necessary to produce the full effect of fire. Occasionally the co-operation of the cavalry may be limited to protecting the artillery while taking up a position, whence it can suddenly open a rapid fire on the enemy."] [Footnote 40: "Cavalry in Future Wars," Part I, chap. v.] [Footnote 41: According to the French General Staff history, this cavalry met a battalion of the 25th Regiment of the 6th Corps, as well as the 3rd Chasseur Battalion and a battalion of the 27th Regiment of the 2nd Corps. At all events, the attack met, not retiring, but unshaken troops.] [Footnote 42: Five German miles = 23 English miles.] [Footnote 43: "Should the issue of the battle prove unfavourable, the cavalry must strain every nerve to facilitate the _retreat_ of the other arms. It is just in such cases that they must assume a relentless offensive. Repeated attacks on the flanks of the pursuing troops will produce the best results. "Even temporary relief for the retreating infantry and a short gain in time may avert utter defeat. The cavalry which effects this will, though it gains no victory, retain the honours of the day."] [Footnote 44: Échelon formations are those in which lines or bodies of troops are placed not directly in rear of each other, but with the second line to the right or left of the first and the next similarly placed--"like steps of stairs"--hence the name. "Échelon" means literally a "step" or the "rung of a ladder."--Editor's Note.] [Footnote 45: "As a rule, a single regiment attacks in line. It may, or may not, be in échelon. Only on exceptional occasions should one of the squadrons follow as a second line. "The officer commanding will bring the directing squadron into the direction of the attack. The squadrons, each in close formation, must be led so as to ensure combined action. "The échelons will envelop the hostile flank or ward off the enemy's flank attacks; they can also be used to prolong the front of the regiment, or they can turn against portions of the enemy which have broken through." "When attacking _cavalry_, the regiments will, as a rule, be employed in a line formation side by side; this will prevent their personnel from becoming mixed up. The necessary depth will be supplied by the regiments themselves, and, in this case, it is usually in the form of échelons. _If the situation demands, even single squadrons can follow in column formation._ "The employment of several lines may be useful on occasions when the situation demands rapid action from the leading regiment, and circumstances will not permit of the rear regiments taking ground to a flank."] [Footnote 46: "When advancing to attack _cavalry_, the divisional commander will, as a rule, order the brigades into _échelon formation_. _Brigades will make independent arrangements as regards formation in depth and for flank protection._