A pleasant breeze blowing down the harbour the boats made sail, and in a few hours reached the ships. The next day the _Tudor_ and _Supplejack_ were again at sea, having received orders to cruise along the Brazilian coast in search of slavers. The ships got some way to the northward of Rio when Murray directed Jack to keep in shore as close as he could venture, while he himself stood off the land; they might thus hope to fall in, either with vessels fitted for the slave-trade about to cross to the African coast, or with full slavers attempting to make a Brazilian port. The latter class it was of course the most desirable to capture, though should the former be taken it would materially assist to put a stop to the traffic, and save a certain number of blacks from undergoing, for a time, at all events, the horrors of a middle passage. The _Tudor_ shortly after daybreak was standing in under easy sail for the land, when from the masthead a schooner was observed, beating up against the breeze, which then blew off the shore, the rays of the rising run striking her canvas bringing her clearly into view. Murray ordered all sail to be made, and hoped to gain on the chase before the corvette was observed by her. As the _Supplejack_ was likely to be inside of her, there was every probability of her being caught by one or the other. It was soon evident, however, that she had made out the corvette, as she was seen to set all sail, and to stand away to the northward: as the _Tudor_ was a long way to leeward, the chase would probably be a long one. From the appearance and movements of the schooner Murray was convinced that she was a slaver with a cargo on board, and he determined therefore to persevere till he could come up with her, and ascertain her real character. The land was barely visible, and the _Supplejack_ might therefore be a long way off in shore, and not yet have caught sight of the chase. The day wore on, and the _Tudor_ had gained considerably on her, when about six bells in the forenoon the sails gave some ominous flaps against the masts, and the wind dropping more and more, the corvette lay almost becalmed, with only just steerage way. As the schooner was, however, likewise almost becalmed she did not gain any advantage from this circumstance. A light wind, in a short time, again filled the corvette's sails; but as it was continually shifting, all hands were on deck employed in hauling on the braces, as necessity required. Now the corvette gained slightly on the chase, now the schooner's sails felt the breeze, and she once more glided along through the smooth water. "She seems to be heaving something overboard, sir," said Desmond to Higson, who was standing on the forecastle with him.