The neck iron was fitted to slaves who made repeated attempts to escape. Imagine a very thick collar, with a thick rod either to the right or the left that extended as far as the head and was locked from behind with a key. It was, of course, heavy, but was intended not so much as a punishment as a sign. Any slave who ran away wearing one of these would instantly be identified as a repeat offender and quickly recaptured.

Half a century ago, slaves often ran away. There were large numbers of them, and not all enjoyed enslavement. They would sometimes be beaten, and not all of them liked being beaten. Many would merely receive a reprimand, either because someone in the household would speak up for them or because the owner wasn’t necessarily a bad man; besides, a sense of ownership moderates any punishment, and losing money is not itself without pain. There were always runaways, though. In a few rare cases, a contraband slave who had just been bought in the Valongo slave market would immediately escape and race off down the streets, even though he didn’t know the town at all. Those who stayed put—usually the ones who already spoke Portuguese—would arrange to pay a nominal “rent” to their master and then earn their living outside the house as street vendors.

A reward was offered to anyone who returned a runaway slave. Advertisements were placed in the local newspapers, with a description of the fugitive, his name, what he was wearing, any physical defects, the area where he had last been seen, and the amount of the reward. When no amount was given, there would be a promise: “will be handsomely rewarded” or “will receive a generous reward.” The advertisement would often be accompanied at the top or the side by a drawing of a black figure, barefoot and running, with, on his shoulder, a stick with a small bundle attached. It also carried a warning that anyone sheltering the runaway would feel the full force of the law.

Now, pursuing fugitive slaves was one of the trades of the time. It might not have been a very noble profession, but, since it involved helping the forces who defend the law and private property, it had a different sort of nobility, the kind implicit in retrieving what is lost. No one took up that trade in the pursuit of entertainment or education; other reasons lay behind such a choice for any man who felt tough enough to impose order on disorder: poverty, a need for money, a lack of any other skills, pure chance, and, occasionally, the desire to be useful, at least to one of the parties.