It was approaching nightfall when, from his post of observation on the roof of Tobar, Jack saw that the French had completed their work. He could just perceive the muzzle of their gun, carefully blinded with beams, protruding from a sort of screen in the ruins of the second house from Vallejo. He was confident that they would not begin their bombardment until the following morning, and he hoped to use the hours of darkness to place his own gun. Before darkness fell, with Don Cristobal's help he took, from several points, careful observations of the position of the French gun, and on the stone floor of the room opening on to the patio in Vallejo he drew chalk lines indicating what appeared to be a suitable position for his eight-pounder.
As soon as it was dark he set two men to break a way with picks through the wall of the patio, at a spot where there was a window. The work was carried out with the aid of dark lanterns, large pieces of cloth being hung over every gap to conceal any glimmer of light from the French. The gun was then hauled through the hole and laid by the chalk lines; it was screened with bags of earth, and then, after it had been loaded with ball, a horse-blanket was hung over the muzzle, which alone was in sight of the enemy.
"Now we can get some sleep, Señor," said Jack. "We've had a hard day's work. I confess I'm longing for the morning, to see whether we can once more get in first. You have arranged the sentries for the night?"
"Yes. Nothing has been neglected."
"A special guard for the gun?"
"Antonio and two of his guerrilleros will take turns through the night."
"We haven't any better men. I can hardly keep my eyes open. Come along."
There was but a faint glimmer of light beyond the Ebro when Jack again took his place beside the gun.
"I'm not a gunner," he remarked to Don Cristobal, "but I fancy I can manage to lay and fire it myself; it's point-blank range, you see; I can hardly miss. Now, hombres," he said, turning to the eight men with him, "everything depends on our shooting first, so keep as mum as door-mats."
Waiting till the increasing light showed him clearly the muzzle of the enemy's gun, he carefully pointed his own piece. He aimed at a beam covering the gun at a point which, as nearly as he could judge, corresponded with the trunnion. Don Cristobal watched him anxiously as he lit the match. What would be the result of the shot? One moment of suspense, then Jack applied the match; there was a flash and a roar, followed immediately by the crashing of timber.