Olaudah Equiano's purpose for writing his narrative was to tell the truth of conditions of life for slaves, particularly in crossing the Atlantic Ocean.
In order to achieve this purpose, Equiano used particularly vivid descriptions and sensory details for just about every sense.
The stench of the hold while we were on the coast was so intolerably loathsome, that it was dangerous to remain there for any time, and some of us had been permitted to stay on the deck for the fresh air; but now that the whole ship's cargo were confined together, it became absolutely pestilential. 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. This produced copious perspirations, so that the air soon became unfit for respiration, from a variety of loathsome smells, and brought on a sickness among the slaves, of which many died, thus falling victims to the improvident avarice, as I may call it, of their purchasers. This wretched situation was again aggravated by the galling of the chains, now become insupportable; and the filth of the necessary tubs, into which the children often fell, and were almost suffocated. The shrieks of the women, and the groans of the dying, rendered the whole a scene of horror almost inconceivable.
Some of the sensory details in this passage include that relate to the sense of smell include the stench of the hold, the air became unfit for respiration, and a variety of loathsome smells. Details relating to feeling include galling of the chains, almost suffocated, heat of the climate, and so crowded that each had scarcely room to turn himself. The last sentence of the passage offers two hearing details. The bold statement offers the visual sense. All these descriptors fall under the literary device imagery.
The diction Equiano chooses to use further specifies the pain these people endured. Words like horror, skrieks, pestilential, and loathsome paint the dire scene that they lived through.
He further develops this scene by blaming these indecent acts on the improvident avarice of the slave traders. This essentially means that they were greedy and their greed created a short-sightedness in them. Had they planned to sell all of these people, they might have taken some precautions to make sure that they would survive the trip across the ocean. This greed can certainly be seen as a theme throughout his entire narrative.