Channels having been made through the sunk vessels with which the Spaniards had blocked up the entrance to the harbour, the FIFTEENTH and twenty-fourth re-embarked, and commenced landing near the city of Carthagena. From the place of landing, the two regiments advanced along a defile, preceded by the grenadiers, through a country covered with trees and herbage of luxuriant growth, the interwoven branches forming a shelter impenetrable both to heat and light, and several men were wounded by shots fired from the tracks and openings into the wood. Diverging from the defile, the two regiments encountered a body of Spaniards advantageously posted to dispute the passage, but as the grenadiers sprang forward to commence the attack, the enemy fled. The two regiments proceeded to the vicinity of the castle of _St. Lazar_, which commands the town, and were followed by the six battalions of marines. The soldiers passed three nights in the open air, for want of tents and tools, and their health was seriously injured. The siege of the castle was commenced; and as the men were fast decreasing in numbers from the effects of hard duty and climate, Brigadier-General Wentworth was induced to attack the place by escalade, to which dangerous enterprise he was urged by Vice-Admiral Vernon. Twelve hundred men stormed the enemy's entrenchments under the walls of the fort, exposed to a heavy fire of musketry. The grenadiers, led by Colonel Grant, rushed forward with astonishing bravery, and leaping into the lines, carried the works in gallant style. The Spaniards fled over a drawbridge into the fort. The British pursued, and called for ladders to storm the fort; but the fire was so hot, that the Americans who carried the ladders threw them down and fled. Meanwhile the storming party was exposed to a destructive fire. At length three ladders were brought forward, and a serjeant and ten grenadiers mounted the walls, but were instantly cut to pieces, excepting the serjeant, who saved himself by leaping down again. Several of the ladders were found too short: it was ascertained that, owing to a guide having been killed, the attack had been made on the strongest part of the works; Colonel Grant fell mortally wounded; and after sustaining a most destructive fire for several hours with intrepidity and perseverance, the troops were ordered to retire, having sustained a severe loss in killed and wounded. Violent periodical rains commenced; the country was deluged with water, and the change of atmosphere produced fatal effects on the health of the men, who were drenched with rain. All hope of further success immediately vanished, and the troops returned on board the fleet, where numbers died from the distempers peculiar to the climate.