Just before sunset we discovered that she had another vessel in company. We lost sight of them after sunset, but, continuing our course in-shore, about nine o’clock, with the assistance of a bright moon and a night glass, we discovered three vessels at anchor off the river St. Barbara. They were all of them slavers belonging to the Havana--the _Fecilidades_, brig, carrying 2 guns, 228 tons, 42 men, and the _Maria Segunda_, schooner, 1 gun, 107 tons, 28 men. One of them was prepared to take in a cargo of slaves, the others, a brig and schooner, had lately arrived, and had not yet got rid of their trading cargo. They had more the appearance of yachts than slavers. Three days afterwards, the _Maria Segunda_, with slaves on board, escaped from the _Waterwitch_ boats. Her gig was the only boat that got hold of her. She was commanded by a midshipman named Bowles, who held on a quarter of an hour after he had one killed and another man wounded out of a crew of four. The slaver had eight men killed. Mr. Bowles used a fowling-piece, with which his coxswain remarked he picked them off as if he had been shooting larks. The cutter and pinnace never succeeded in getting alongside, although they exchanged shots. The slave trade will never be put a stop to unless by the consent of the European Powers. Although the Spaniards and a few Portuguese and Brazilians are the only fellows who have enterprise sufficient to engage in the trade, there is not a vessel on the coast that is not supplied with papers allowing her to wear the colours of other nations; the Spanish flag is nearly the only one that is never seen. A beautiful Spanish brig which fitted out at Barcelona, close to us, was found under Russian colours. Lieutenant Hill, of the _Saracen_, having boarded a brigantine manned by Spaniards, but under Portuguese colours, had her Captain on board with his papers, and on Hill telling him his papers would not do, as they mentioned he was manned with two-thirds Portuguese, he exclaimed: “I am the most unfortunate fellow in the world. This is the third vessel I have lost in two years. That blackguard at Porto Praya told me they were all correct, and I paid him a thousand dollars.” But Hill could not detain him. Last year there were upwards of 30,000 negroes taken off from the coast of Africa, to the northward of the “Line.” In spite of the vigilance of about thirteen of our cruisers, nine out of ten slavers escape. I have no doubt that as many more slaves are shipped to the southward of the “Line.” For every slaver taken by the British cruisers, an extra price is put on the slaves when they arrive at their destination; and, as their value increases, so will the number of vessels employed.