He ordered Vandamme to march at 6 A.M., and Gérard at 8 A.M. Now, at that time of year, it was light enough to march at 3.30 A.M., hence Grouchy wasted another valuable two and a half hours, when time was all-important. Again, there was no necessity to keep Gérard’s Corps waiting for Vandamme’s to get ahead, as there were no less than four roads from Gembloux towards Corbaix, and the two inner ones could easily have been used for this march. But the troops were still further delayed. Their breakfasts were not ready for them, and Vandamme’s Corps did not start until nearly eight o’clock. They had had twelve hours in bivouac at Gembloux, and yet their breakfasts could not be ready by 6 A.M.! Excelmans’ men at Sauvenière, too, were not in the saddle until 6 A.M. Grouchy himself left Gembloux at 8.30 A.M. He overtook Vandamme’s Corps at Walhain at about 10 A.M., and here he dismounted for breakfast, allowing the troops to march on. At half-past ten, Excelmans’ advanced guard came into touch with Thielemann’s rear-guard, on the road to Wavre near La Baraque. This news was sent back to Grouchy, while Excelmans extended his men and engaged the Prussians lightly. At Walhain, Gérard, having ridden ahead of his troops, joined Grouchy, and during their breakfast, the sound of heavy firing in the direction of Mont St Jean was heard from the garden of the house where they had stopped. (This was the opening cannonade of the battle of Waterloo, which began at half-past eleven.) Gérard at once urged Grouchy to change his direction and march to the sound of the cannonade. But Grouchy refused to take the responsibility of disobeying the orders he had received from Napoleon--“to pursue and attack the Prussians, and on no account to lose sight of them.” Having received, a few minutes before, Excelmans’ report from the front, he considered that he was moving in the right direction. To march across country to join Napoleon would have been contrary to his orders. To send a part of his forces across the Dyle would be to separate his army at a most dangerous moment. But this was just one of those cases when instructions need not have been implicitly obeyed. Circumstances had altered considerably since Grouchy had received his orders from Napoleon. A resolute and capable commander, in Grouchy’s place, would have marched with his whole force by St Géry and Moustier from Gembloux at daybreak on the 18th. Certainly it would have been a mistake to divide his army at this time, but Grouchy should without doubt have taken upon himself the responsibility of digressing from his original instructions, and he would have been justified by the change in circumstances.