Clock? I think. I know they invented the calendar
prior to European colonization in Africa, slavery had already existed between the people there, slave owners would willingly offer their slaves to the Europeans in order to protect them selves, the europeans can argue that they did not establish slavery, rather, they continued work that seemed beneficial to them.
foreshadowing provides hints as to what will happen. it is often difficult to spot, but is noticed if looked for.
