He sent an orderly to find out what the newcomers were. The orderly returned to report that the troops were Erlon's, but that they had turned back. Had Napoleon sent again, after this, to find Erlon, and to make him for a third time change his direction, it would have been altogether too late to have used Erlon's corps d'armée at Ligny by the time it should have come up. Napoleon had, therefore, no course before him but to do as he did, namely, give up all hope of help from the west, and defeat the Prussians at Ligny before him, if not decisively, at least to the best of his ability, with the troops immediately to his hand. * * * * * So much for Erlon. Now for the second point: the way in which the units of Wellington's forces dribbled in all day haphazard upon the position of Quatre Bras. Wellington, as we saw on an earlier page, was both misinformed and confused as to the nature and rapidity of the French advance into Belgium. He did not appreciate, until too late, the importance of the position of Quatre Bras, nor the intention of the French to march along the great northern road. Even upon the field of Waterloo itself he was haunted by the odd misconception that Napoleon's army would try and get across his communications with the sea, and he left, while Waterloo was actually being fought, a considerable force useless, far off upon his right, on that same account. The extent of Wellington's misjudgment we can easily perceive and understand. Every general must, in the nature of war, misjudge to some extent the nature of his opponent's movements, but the shocking errors into which bad staff work led him in this his last campaign are quite exceptional. Wellington wrote to Blucher, on his arrival at the field of Quatre Bras, at about half-past ten in the morning, a note which distinctly left Blucher to understand that he might expect English aid during his forthcoming battle with Napoleon at Ligny. He did not say so in so many words, but he said: "My forces are at such and such places," equivalent, that is, to saying, "My forces can come up quite easily, for they are close by you," adding: "I do not see any large force of the enemy in front of us; and I await news from your Highness, and the arrival of troops, in order to determine my operations for the day." In this letter, moreover, he said in so many words that his reserve, the large body upon which he mainly depended, would be within three miles of him by noon, the British cavalry within seven miles of him at the same hour. Then he rode over to see Blucher on the field of Ligny before Napoleon's attack on that general had begun. He got there at about one o'clock.