This was the final pass; and after marching some twelve miles farther, one saw at the left edge of a sandy, gravelly plain, set with occasional tufts of coarse grass, the dust-brown castle of Perote and, seemingly just above it though in reality several miles distant, the pine-clad mountain of that name. The castle was a superb specimen of military architecture, capable of accommodating more than 2000 men; but it had long served chiefly as a state prison, a refuge for troops, an arsenal, and a dépôt for the rich convoys that went this way. The American troops could have passed by on the other side of the plain, had that been necessary; but it was not. With only twenty-three gunners and scarcely any powder, General Gaona could not have defended the place. Canalizo therefore ordered him to evacuate it on the nineteenth; and at noon on the twenty-second Worth took possession of its elaborate bastions, more than fifty cannon, more than 25,000 balls and shells and even 500 muskets, which the terror-stricken Mexicans had not cared to remove. Throwing Garland's brigade and Duncan's battery about fifteen miles in advance to facilitate the gathering of subsistence, Worth now halted in accordance with his orders.[24.1] [SCOTT'S DIFFICULTIES] Scott meantime remained at Jalapa to study his problems and make his preparations. The capital of Mexico, he believed, lay at his mercy, and this opinion seems to have been correct; but unlike his critics, who merely had to deal with legions of ink on areas of paper, he found that much needed to be done before seizing it. The position of the Americans depended vitally on military prestige, and it was therefore of the utmost importance to suffer no reverse. His first care was to make sure of getting up in advance of the especially fatal rainy season, which was expected to begin at the latest by the first week of June, the needful clothing, equipments, ammunition, salt, medicines and many other imported articles; and since the lack of cavalry and a due regard for the health of the troops forbade trying to keep the road below Cerro Gordo clear of Mexicans, this tedious work involved the use of heavily escorted convoys,[24.2] and the exercise of unceasing vigilance, energy and skill.[24.6] [Illustration: Profile of the Route from Vera Cruz to Mexico]