But _I_ had a duty to perform before I cast off from the buoy at which the brigantine was straining; therefore, while the other vessels got under way, I and my boat's crew stood on the wharf and quietly watched them go.  Then, as soon as the brig was fairly clear of the anchorage, I went, with two of my boat's crew, to the leewardmost building of the settlement and set light to a little pile of combustibles that had been carefully arranged in each room, finally thrusting a blazing torch into the thatch upon quitting the building.  And in the same way we proceeded to each building in turn, until the entire settlement, barracoons and all, was a roaring furnace of flame.  Then, bidding my crew get down into the boat and stand by to shove off in a hurry, I proceeded to a certain spot and set fire to an end of slow match that was protruding from a box sunk into the ground near the wharf face, after which I picked up my heels and scampered off, best leg foremost, for the boat, into which I sprang, without much consideration for my dignity, and gave the word to shove off.  The boat's crew, who were fully aware of my reasons for haste, lost no time in obeying the order, and the next instant we were foaming away toward the brigantine, from the deck of which the hoarse voice of Tasker, the gunner's mate, now reached us, bawling an order for those for'ard to "stand by to slip!"  But before we were half-way across the intervening stretch of water a dull "boom" resounded astern of us, and a length of some fifty feet of wharf face suddenly leapt outward and fell with a heavy splash into the water, followed, about half a minute later, by a second "boom" and splash, then a third, fourth, fifth, and so on, until the entire wharf was completely destroyed and the whole place a ghastly, fire-swept ruin.  Then we, too, turned our backs upon what, a short time before, had been one of the most extensive, important, and conveniently situated slave factories on the whole of the West Coast, and made sail to rejoin our companions.  We overtook them about half a mile outside the bar; and when I had signalled the commodore that my mission of destruction was fulfilled, he hoisted a general signal setting a course of north-west by west for Cape Palmas; and, when this had been acknowledged, hoisted another to "try rate of sailing."  This, of course, was the same thing as giving the word for a race, and, the weather being moderate at the time, we each at once proceeded to pile upon our respective commands every rag of canvas that we could find a yard, boom, or stay for.