The infographic uses capital letters in the title, along with italics. For the body text, the script is cursive. The small capitals are used to label the different parts of the slave ship.
The colors used are black and white for minimal distraction. There is a drawing of the section of the ship along with a scale to communicate the size relations. The labeling of the Figures seems to be out of order from VII to IV, but it may have been a choice to arrange the diagram with the heaviest ink communicated the density of packed human bodies at the very end of the diagram.
The Brooks slave ship infographic is absent of color but size is key in understanding the design. The slaves are proportional to the ship and to each other, considering this diagram was used to pack in as many slaves as possible. As well, multiple views of the ship are provided in order for the reader to accurately decipher the diagram and properly load slaves in this ship. Although the sketch does not accurately portray the amount of slaves that could actually fit on the ship (400 in diagram, 454 in real life), it shows the inhumane nature of slavery--which is what this diagram eventually came to stand for.
This Diagram was originally published in 1788 by slavery abolitionists. While this diagram was originally intended for someone loading a slave ship, it became a symbol of the fight against slavery in the United Kingdom and the United States in the late 18th century. Those for the abolition of slavery used the very same tool the slave-traders used in order to get their point across. They are not simply making a propaganda tool for their cause, they are taking an actual part of the slave trade to expose how cruel it was.
The overwhelming repetition of bodies in the diagram illustrates the tight and crowded conditions in these ships while the multiple diagrams reveal how layered these bodies were (cutaway views of the ship). The eye naturally looks at Figure IV because it has the heaviest amount of ink and is frankly the most shocking diagram in the image. The large density of human shapes drawn in ink communicate the large amount of humans that can fit in the slave ship. The abolitionists published this diagram with the purpose of showing the inhumane conditions of slavery in mind.
Merchant Slave Trader
For the British Slave Trader, it would have been a diagram for how to load slaves in a ship as dense as possible for the greatest profit and efficiency.
Society for Effecting the Abolition of the Slave Trade in Plymouth
The diagram was published by the Plymouth chapter for the Society for Effecting the Abolition of the Slave Trade in Plymouth and the purpose was to communicate the horrid conditions aboard the slave ships through the sheer density of the human shapes represented in the diagram.