Manacles, like those above, seem to have been present for at least the last 400 years, though the actual age seems to be in debate among historians.  The bar between the manacles is an even more debatable point. Spreader bars made it difficult for a prisoner to move and seem useful only to prevent a slave from escaping in the night. As far as our research can ascertain, they were not used in war time and therefore were not widely used after the civil war. Blackened and finished with beeswax.