The illness of Centeno was known in the army of Gonzalo, and that his tent was pitched at some distance from the rest, to avoid the noise and bustle of the camp. Founding on this intelligence, Juan d'Acosta was detached with twenty picked men, with orders to approach silently in the night to the camp of the royalists, and to endeavour to carry off Centeno. Acosta accordingly drew near with so much caution that he surprised the centinels that were on guard over Centeno, and had very near reached his tent when the alarm was given by some negro servants. Being thus discovered, Acosta ordered his men to fire off their musquets, and immediately retreated back to the camp of Gonzalo without losing a man. In the confusion occasioned by this exploit, great numbers of the royalists hastened towards the tent occupied by Centeno; but on this occasion several of the soldiers belonging to Valdivia threw away their arms and fled. Next morning the scouts of both armies approached each other, followed by the respective armies, which at length came in sight. The army of Centeno consisted of about a thousand men, two hundred of whom were cavalry, an hundred and fifty armed with musquets, and all the rest with pikes. Of this army, Luis de Ribera was major-general, Pedro de Rios, Jerom Villegas, and Pedro de Ulloa, captains of cavalry, and Diego Alvarez carried the grand-standard. The captains of infantry were Juan de Vargas, Francisco Retamoso, Negral, Pantoia, and Diego Lopez de Zuniga; Luis Garcias being sergeant-major, or adjutant-general[33]. The army of Gonzalo consisted only of five hundred men, of which three hundred were musqueteers, and eighty cavalry, the remainder being armed with pikes. Of this army Carvajal was lieutenant-general; the licentiate Cepeda and Juan Velez de Guevara were captains of horse; and Juan d'Acosta, Ferdinand Bachicao, and Juan de la Torre captains of foot. [Footnote 33: It is not easy to understand how Mendoza, who had joined Centeno some time before, happens to be omitted in this enumeration--E.]