Description from Olaudah Equiano autobiography describing the middle passage:
The closeness of the place, and the heat of the climate, added to the number in the ship, which was so crowded that each had scarcely room to turn himself, almost suffocated us. The air soon became unfit for breathing, from a variety of loathsome smells, and brought on a sickness among the slaves, of which many died. This wretched situation was made worse by the chains. The shrieks of women, and the groaning of the dying, created a scene of horror almost unbelievable. Three desperate slaves tried to kill themselves by jumping overboard. Two drowned, the other was captured and beaten unmercifully. When I refused to eat, I too was beaten.
The interesting life of Olaudah Equiano 1789