 On 15 October Ney's troops successfully charged the Michelsberg encampments and on the 16th the French began to bombard Ulm itself.Austrian morale was at a low point and Mack began to realize that there was little hope of rescue.On 17 October Napoleon's emissary, Ségur, signed a convention with Mack in which the Austrians agreed to surrender on 25 October if no aid came by that date.