midnight
We then fixed the peremptory night , and I was to wait at the water-side and get the boats in readiness . The prison they were in was a Portuguese fort , which had been deserted ever since the building a much better on the other side of the river , a gunshot lower . It was built with walls too thick for naked men to storm ; the captives were securely locked up every night ; and two soldiers , or sentinels , kept watch in an outer-room , who were relieved from the main-guard in the body of the building . The expected night arrived , and a little before midnight , as had been concerted , one of the prisoners cried out he was so parched up he was on fire , he was on fire ! The sentinels were both asleep , but the first that waked called at the door to know what was the matter . The prisoner still crying out , `` I am on fire ! '' the rest begged the sentinel to bring a bowl of water for him , for they knew not what ailed him .