Soon after Oglethorpe returned to Savannah he saw that trouble was brewing with the Spaniards. He heard that a large troop of soldiers had lately marched from St. Augustine. He knew that there was a garrison of three hundred foot-soldiers and fifty horse at St. Augustine, with reinforcements coming from Havana, and that he had not a single regular soldier with which to oppose them. Then word came that a fleet of strange ships had been seen at sea. He ordered his colonists to strengthen their fort at once, and set out in a boat for St. Andrews to learn exactly how matters stood. From Fort St. George he crossed to the Spanish side of the St. Johns River, and climbing a hill, fastened a white flag to a pole, hoping the Spaniards would come to a conference with him. None came, however, but fires were seen on the Florida side that night, and the governor thought the Spaniards were planning an attack. He ordered two gun-carriages and two swivel-guns taken into the woods and placed at different points. The larger guns were to fire seven shots, and the smaller to answer with five. The latter would sound like a distant ship firing a salute, and the larger guns would resemble the noise of a battery returning the salute. In this way Oglethorpe hoped to make the Spaniards think that reinforcements were coming to the aid of the Georgians. By this trick Oglethorpe escaped great danger. As a matter of fact the Spanish governor had arrested Oglethorpe's messengers, and had sent a strong force to attack the fort on St. Simons Island. The battery there, however, drove the Spaniards out to sea again, and when they tried to approach by another inlet they were driven off the second time by the garrison at St. Andrews. They then decided to attack St. George, but as they were planning this they heard the booming of the distant cannon, thought reinforcements must be arriving, as Oglethorpe had figured on their thinking, and decided not to make the attack at all then. At the same time Oglethorpe lighted fires in the woods, thereby making his enemy believe that Creek Indians were coming to join the English. The Spanish commander, Don Pedro, gave the order to return to the walls of St. Augustine, and there, by his reports of the numbers of Oglethorpe's troops, induced the Spanish governor to send back Oglethorpe's two agents, and with them one of his own officers to urge the Englishman to keep his Indian allies from invading Florida.