The capital was well prepared for defense. The forts, as now existing, were completed, and the city surrounded by a wall the strength of which may be estimated by the appearance of the parts still intact. On these defenses 376 pieces of cannon of different caliber were planted, besides 35 mortars, 4 howitzers, and 3 swivel guns. The garrison was reduced to about 200 men, part of the troops having been sent to la Española to quell the insurrection of the negro population led by Toussaint L'Ouverture. There were, besides these 200 veteran troops, 4,000 militiamen, about 2,000 men from the towns in the interior (urbános) armed with lances and machetes, 12 gunboats and several French privateers, the crews of which numbered about 300. Abercrombie landed on the 18th at Cangrejos (Santurce) with 3,000 men, and demanded the surrender of the city. Governor Castro, in polite but energetic language, refused, and hostilities commenced. For the next thirteen days there were skirmishes and more or less serious encounters on land and sea. On the morning of the 1st of May the defenders of the city were preparing a general attack on the English lines, when, lo! the enemy had reembarked during the night, leaving behind his spiked guns and a considerable quantity of stores and ammunition. [Illustration: Fort San Geronimo, at Santurce, near San Juan.] The people ascribed this unexpected deliverance from their foes to the miraculous intervention of the Virgin, but the real reason for the raising of the siege was the strength of the fortifications. "Whoever has viewed these fortifications," says Colonel Flinter,[44] "must feel surprised that the English with a force of less than 5,000 men should lay siege to the place, a force not sufficient for a single line along the coast on the opposite side of the bay to prevent provisions from being sent to the garrison from the surrounding country. Sir Ralph's object in landing, surely, could only have been to try whether he could surprise or intimidate the scanty garrison. Had he not reembarked very soon, he would have had to repent his temerity, for the shipping could not safely remain at anchor where there was no harbor and where a dangerous coast threatened destruction. His communication with the country was cut off by the armed peasantry, who rose _en masse_, and to the number of not less than 20,000 threw themselves into the fortress in less than a week after the invasion, so that the British forces would, most undoubtedly, have been obliged to surrender at discretion had the commander not effected a timely retreat."