It was as Pringle said.  A light draught of air had suddenly sprung up exactly where the brig happened to lie; and by the time I had got my telescope once more focused upon her, she was again heading up for us, with her weather braces slightly checked, and quite a perceptible curl of white foam playing about her sharp bows.  But it only helped her for about half a mile, and then left her completely becalmed, as before, while we were still stealing along at the rate of perhaps a knot and a quarter per hour.  The skipper of the brig allowed some ten minutes or so to elapse, possibly waiting for another friendly puff of wind to come to his assistance, but, seeing no sign of any such thing, he hoisted out his longboat, lowered a small gun--to me it looked like a 6-pounder-- into her, and dispatched her, with two other boats, in chase of us.  The dogged determination which animated our pursuers was clearly exemplified by their behaviour; they made no attempt to cross with a rush the stretch of water intervening between us and them, but settled down steadily to accomplish the long pull before them as rapidly as possible consistent with the husbanding of their strength for the attack when they should arrive alongside.  As they pushed off from the brig she fired a gun and hoisted Brazilian colours.