two o'clock
Our own gunboats were hindered , by the same cause , from putting out and opening a flanking fire upon the battering ships . The northern batteries , by the water , suffered heavily from the fire of the Spanish lines ; which took them in flank and , indeed , some of the batteries in reverse , causing many casualties . The Artillery , however , refused to let their attention be diverted from the battering ships . By two o'clock the furnaces had heated the shot in all the batteries and , although some of them had been firing these missiles for upwards of an hour , it was not until two that their use became general . Soon afterwards -- when the wind cleared away the smoke from the ships -- men could be seen on their sloping roofs , directing streams of water from the pumps upon small wreaths of smoke that curled up , here and there . Up to this time , the defenders had begun to fear that the craft were indeed as invulnerable as the Spaniards believed them to be ; but these evidences that the red hot shot were doing their work greatly roused their spirits , and cheers frequently rose , as the men toiled at their heavy guns . As the afternoon went on , the smoke from the upper part of the Spanish admiral 's flagship rose more and more thickly and , although numbers of men continued to bring up and throw water over the roof -- working with extraordinary bravery , in spite of the hail of projectiles poured upon them -- it was clear that the fire was making steady progress .