The allied leaders had, after a council of war on the 23d of January, at Nandaime, appointed a general-in-chief, and heads of the several departments. The chief command was conferred on Florencio Xatruch.[XVII-44] His tenure lasted but a few days, José Joaquin Mora being finally selected by the governments commander-in-chief, when he was recognized as such in general orders of February 19th and 20th.[XVII-45] The allies came to the conclusion that it was advisable to closely besiege the enemy rather than to attempt further assaults. Xatruch occupied and held, March 26th, the barrio de la Puebla, south of the city, which was the only means of free ingress and egress for the filibusters. Thus was Walker penned. But his friends abroad had not forgotten him. Three Americans, Lockridge, Anderson, and Wheat, brought 500 men to San Juan del Norte in March, and undertook to ascend the river. Lockridge occupied La Trinidad, but Titus was repulsed at the fort. They then concluded to invade Costa Rica, as was then supposed, for they essayed to go up the Sarapiquí; but soon after entering the river their steamer blew up, and the expedition came to naught.[XVII-46] The besieged, on hearing of the arrival, April 3d, with reënforcements, of General Martinez, whose prowess they had learned to respect, became alarmed, and the next day eighty deserters entered the allied lines. An assault in force was made April 11th, which failed. Walker's casualties were quite small, while those of the assailants were heavy.[XVII-47] The latter secured possession of San Juan del Sur, in order that Walker should receive no further aid from that quarter. It was now evident that the filibusters could not hold out much longer. The original force of 1,000, though more or less augmented with the arrival of every steamer, had become reduced to about one half that number. The garrison had an abundance of plantains, but no meat other than that of asses, mules, and horses. [Sidenote: CAPITULATION OF WALKER.]