It took another five days for the tunnel to be dug under the foundations of the bastion.The engineers packed the small space with barrels of gunpowder, laid a fuse and withdrew from the tunnel. Once again the approach trenches were filled with assault troops as they waited for the moment to attack. When all was ready, the chief engineer lit the fuse and fell back as it sputtered brightly into the darkness of the tunnel. Every man in the French army watched in tense silence, necks and shoulders strained as they braced themselves against the blast.When it came there was a sheet of flame from the end of the tunnel and the ground at the base of the bastion blew up into the air.A shower of rock, stones, soil and dust shrouded the scene. Napoleon felt the tremor pass through the ground under his feet and then the air was filled with the roar of the detonation.

At once, every man on the staff and the assembled senior officers strained to pick out the detail through the slowly clearing pall of dust. Then a puff of wind from the sea cleared the view and Napoleon’s heart sank. The only sign of damage was the collapse of a stretch of the battlements and a small crack that ran only halfway up the wall.There was nothing for it but to call off the attack, and the men trudged back from the approach trenches to their tents in the camp.

The field guns resumed their bombardment of the wall, with the same dispiriting lack of effect, day after day, until Berthier brought it to Napoleon’s attention that their stock of ammunition was running dangerously low.The next day the army headquarters issued a proclamation offering a bounty on any enemy cannon balls that could be retrieved from the ground in front of the walls. Those men who still had enough spirit of adventure amused themselves with daring sprints from their trenches to grab the nearest ball and then hurry back to safety before the Turks could respond with a fusillade of musket fire.A few did not make it, but the steady flow of recovered shot went some way towards supplementing the dwindling supplies in the army’s stores.

The replacement siege guns were landed at Haifa in the middle of April and hauled overland to the siege lines. New, better protected, batteries were constructed on the right flank, and sweating crews manoeuvred the heavy guns into position and brought up the powder and shot ready for the renewed attack on the bastion. They opened fire on the last day of April and Napoleon noted with satisfaction that they were immediately having an effect. Each heavy ball smashed into the city’s defences, dislodging a small fall of masonry. Within a day a practical breach had been opened and the French army prepared itself for another attack.