Buonaparte, uncertain which of these attacks he was to consider as the main one, concentrated his army at Verona, which had been so important a place during all these campaigns as a central point, from which he might at pleasure march either up the Adige against Alvinzi, or descend the river to resist the attempts of Provera. He trusted that Joubert, whom he had placed in defence of La Corona, a little town which had been strongly fortified for the purpose, might be able to make a good temporary defence. He despatched troops for Joubert's support to Castel Nuovo, but hesitated to direct his principal force in that direction until ten in the evening of 13th January, when he received information that Joubert had been attacked at La Corona by an immense body, which he had resisted with difficulty during the day, and was now about to retreat, in order to secure the important eminence at Rivoli, which was the key of his whole position.[215] Judging from this account, that the principal danger occurred on the upper part of the Adige, Buonaparte left only Augereau's division to dispute with Provera the passage of that river on the lower part of its course. He was especially desirous to secure the elevated and commanding position of Rivoli, before the enemy had time to receive his cavalry and cannon, as he hoped to bring on an engagement ere he was united with those important parts of his army. By forced marches Napoleon arrived at Rivoli at two in the morning of the 14th, and from that elevated situation, by the assistance of a clear moonlight, he was able to discover, that the bivouac of the enemy was divided into five distinct and separate bodies, from which he inferred that their attack the next day would be made in the same number of columns.[216] The distance at which the bivouacs were stationed from the position of Joubert, made it evident to Napoleon that they did not mean to make their attack before ten in the morning, meaning probably to wait for their infantry and artillery. Joubert was at this time in the act of evacuating the position which he only occupied by a rear-guard. Buonaparte commanded him instantly to counter-march and resume possession of the important eminence of Rivoli. [Sidenote: BATTLE OF RIVOLI.] [Sidenote: Jan. 14.]