With the shells exploding and the cannon-balls pursuing they made way down the trench, the sailor leaning with his sound arm on Jerry’s shoulders. The sick bay, or hospital, was a sandbag-covered room at one side; not a pleasant place――oh, no, for wounds were being dressed and things were being cut off by the navy surgeon and his assistant. Still, it seemed to be safe from the shot and shell, and there were not many wounded, yet; only four or five. So Jerry lingered, until the surgeon espied him and set him at work picking lint, serving water, and so forth. The reports from the battery were encouraging, judging by the conversation. The six guns were all in action, together: the three Paixhans, which threw shells eight inches in diameter and weighing sixty-eight pounds, and the three solid-shot pieces, which threw balls, six inches in diameter, and weighing thirty-two pounds. These were the heaviest American guns firing yet, for breaching. “Yes, shiver my timbers!” growled Jerry’s sailor to one of the other wounded. “Scott axed for ’em, didn’t he? Would the commodore please to land a few o’ the navy toys and furnish the bass in this here music? Would the navy lend the army some genuyine main-deck guns, of a kind to fire a broadside with and send the bloomin’ dons to Davy Jones? ‘Bless my bloody eyes!’ says the commodore. ‘Sartinly I will, general. But I must fight ’em.’ And ain’t we a-fightin’ of ’em? Well, I guess we are, matie!” So being navy guns, they were being “fought” by the navy. From seven hundred yards their shot and shell were tearing right through the walls of the city. The astonished Mexicans were fighting back with three batteries, all aimed at the naval battery, to put it out. The army was erecting another battery, nearby――Battery Number 4, of the heaviest army cannon, sixty-eight-pounders and twenty-four-pounders. Pretty soon these would join with the navy fire. The work in the sick bay slackened, and Jerry stole up “forward” again. The din and the rush were as bad as ever. The sailors, bared to the waist, were black with powder grime and streaked with sweat, on faces, bodies and arms. The guns were alive and alert――they were monsters, belching, darting back, fuming, while they waited to be fed, then eagerly darting to belch once more. After each shot the gun squads cheered, peering an instant through the fog. “Another for the dons’ lockers!” “Hooray, lads! We’ve cut his bloomin’ flag away.” “No, no! It’s up again.” Yonder, across the heaving plain, the figure of a Mexican officer had leaped upon the parapet of a bastion fort set in the walls and was fastening the Mexican flag to its broken flagpole. It was a brave act. Cheers greeted him. The crew in front of Jerry reloaded at top speed. The great gun spoke.