Nor was the possibility of an attack from the eastward overlooked. On the Morro headland at the important entrance a battery of three guns was placed, well protected by breast-works of timber, stone and earth, and the coast from Morro to Matanzas was continually patrolled by horsemen on the lookout for the coming of strange vessels, and under orders similar to those which had been given to the watchmen at Chorrera. As for the harbor itself, a great chain was stretched across its entrance buoyed with logs and fastened with a huge padlock at the foot of the Morro headland. Finally the few swift sailing vessels which could be mustered into the service were kept cruising off the shore to espy the approaching squadron. They were not sufficiently strong to give battle, but they could give warning to the city. Also they could bear to Spain or to Mexico tidings of what occurred. Thus one vessel lay in the estuary of the Puercos River, ready to flee to Mexico, while another cruised around Ycacos Point, to hasten to Spain to tell if Havana should fall into the hands of the foe. Meanwhile in Havana itself all possible forces were mustered for defense. The volunteers from the other towns were drilled into an efficient state of discipline. Such was their zeal that they gladly served without pay while a considerable number of them in addition provided their own rations at their own cost. For the necessary expenses of their maintenance Rojas, the Royal Treasurer, used what royal funds were in hand regardless of the purpose for which they had been designed, and when these were insufficient he collected taxes without authority, on the principle that the safety of the city and Island was the supreme law. At the beginning of April some welcome aid arrived from Mexico, which even Quinones was now glad to have. The Viceroy sent four vessels, bearing about 300 fighting men, with six months' supplies of food and with pay for eight months in advance. These increased the force under Quinones to more than 900 well-trained soldiers. During the month of April Luzan arrived from Bayamo with nearly 100 more men, thus increasing the garrison of Havana to about 1,000. This was a force which the Captain-General confidently believed would be able to resist and to repulse any force which Drake might be able to land.