Before daybreak on the 8th Napoleon was in the streets of Eylau, forming his line of battle for the coming engagement. Soon the artillery of both armies opened, and a rain of cannon balls began to decimate the opposing ranks. The Russian fire was concentrated on the town, which was soon in flames. That of the French was directed against a hill which the emperor deemed it important to occupy. The two armies, nearly equal in numbers,--the French having 75,000 to the Russian 70,000,--were but a short distance apart, and the slaughter from the fierce cannonade was terrible. A series of movements on both sides began, Davout marching upon the Russian flank and Augereau upon the centre, while the Russians manoeuvred as if with a purpose to outflank the French on the left. At this interval an unlooked-for obstacle interfered with the French movements, a snow-fall beginning, which grew so dense that the armies lost sight of each other, and vision was restricted to a few feet. In this semi-darkness the French columns lost their way, and wandered about uncertainly. For half an hour the snow continued to fall. When it ceased the French army was in a critical position. Its cohesion was lost; its columns were straggling about and incapable of supporting one another; many of its superior officers were wounded. The Russians, on the contrary, were on the point of executing a vigorous turning movement, with 20,000 infantry, supported by cavalry and artillery. "Are you going to let me be devoured by these people?" cried Napoleon to Murat, his eagle eye discerning the danger. [=Murat's Mighty Charge=] He ordered a grand charge of all the cavalry of the army, consisting of eighty squadrons. With Murat at their head, they rushed like an avalanche on the Russian lines, breaking through the infantry and dispersing the cavalry who came to its support. The Russian infantry suffered severely from this charge, its two massive lines being rent asunder, while the third fell back upon a wood in the rear. Finally Davout, whose movement had been hindered by the weather, reached the Russian rear, and in an impetuous charge drove them from the hilly ground which Napoleon wished to occupy. The battle seemed lost to the Russians. They began a retreat, leaving the ground strewn thickly with their dead and wounded. But at this critical moment a Prussian force, some 8,000 strong, which was being pursued by Marshal Ney, arrived on the field and checked the French advance and the Russian retreat. Benningsen regained sufficient confidence to prepare for final attack, when he was advised of the approach of Ney, who was two or three hours behind the Prussians. At this discouraging news a final retreat was ordered. [=The Cost of Victory Frightful=]