three o'clock
Five thousand men garrisoned Weissenfels , but Frederick made short work of the place . His cannon burst down the gates , and his troops rushed forward with all speed ; but the garrison fled across the bridge over the Saale , which had already been prepared for burning ; and they set it on fire in such haste that four hundred were unable to cross , and were made prisoners . The fugitives joined their army on the other side of the Elbe , and its guns opened upon the burning bridge , to prevent the Prussians from trying to extinguish the flames . The Prussians returned the fire , and the artillery duel was kept up until three o'clock , by which time the bridge was consumed . Frederick had already fixed upon a spot suitable for the erection of another , and during the night , while the enemy were falling back to take up a fresh position upon higher ground , the engineers , working diligently , succeeded in throwing a bridge across . Keith arrived at Merseburg the next morning . A strong force lay opposite , ready to dispute the passage ; but when Soubise found that the king was crossing by his new bridge , he called in all his detachments and marched away , to a strong position , and there set himself in array ready to receive an attack .