Floating magnetic needles -- the first compasses -- allowed sailors and traders to chart their course.
(Floating magnetic needles; allowed; sailors and traders to chart their course) Context(Floating magnetic needles allowed,List([0, 59))):(sailors and traders; to chart; their course)
Floating magnetic needles allowed,List([0, 59))
Floating magnetic needles sailors and traders
allowed to chart
sailors and traders to chart their course
their course