"I shall put their money where they have directed me to put it. But I cannot help observing, that the nearly limitless coast of Africa is crowded with slaves, driven out from the interior by their more ferocious cousins, and virtually free for the picking. If I wish to pump water from a Cornish tin-mine, Dr. Waterhouse, I need not pay Mr. Newcomen to erect a frightful Engine; now that we have the Asiento, I need only send a ship southwards, and in a few weeks’ time I shall have all the slaves I need, to pump the water out by stepping on tread-mills, or, if I prefer, to suck it out through hollow straws and spit it into the sea."