By midday we had raised the stranger sufficiently to enable us to see the whole of her royal and just the head of her topgallant-sail from the deck, while from our royal-yard the whole of her canvas was visible down to the top half of her foresail; we were therefore in a position to pronounce not only that she was a brigantine, but also that she was a slashing big craft, probably quite as big as the _Dona Inez_.  As the afternoon wore on, however, we seemed to be raising her no higher, and I came at length to the conclusion that, like ourselves, she had slightly hauled her wind, thus manifesting a distinct if not very strongly marked desire to avoid any closer acquaintance with us, which, in its turn, went far to confirm me in a suspicion which had already arisen within my mind that she was a slaver, probably from the Bonny or the Gaboon, with a cargo of "black ivory" on board.  All the afternoon I maintained a close watch upon the commodore, with the aid of the splendid telescope which we had found aboard the schooner, momentarily expecting him to make some signal which would indicate that he shared my suspicions; but none came, and at length it dawned upon me that he was purposely abstaining from holding any communication with me, lest by doing so he should strengthen any suspicion which the stranger might be entertaining as to our character.  But I noticed that at eight bells in the afternoon watch he again altered his course, hauling up another point; and without receiving any signal from him I promptly did the same.