Timeline: This graph shows the number of Gothic works published per year between 1750 and 1840 (with our four key players depicted in blue). While Otranto is widely considered to be the first Gothic novel, several prior novels featured so-called Gothic motifs; however, it wasn't until the 1790s that the genre really took off. Gothic literary scholar Nick Groom suggests that the sudden popularity of "horrid" novels were a way of responding to the unsettlingly violent stories being reported about the French Revolution and the upheaval of centuries-old structures and institutions (The Gothic, p.86).
Motifs: There are over 450 motifs listed in the dataset. I ultimately decided to display them in a treemap chart so that viewers wouldn't have to scroll to see the whole picture - instead, viewers can hover over the squares to see what motifs they represent. The size of the squares and the depth of color demonstrate the prevalence of some motifs over others within the corpus; for instance, the most commonly used motif - "Fainting (female)" - appears in 104 books (or in half of the corpus). As the squares get lighter and smaller, the motifs they represent appear less frequently among the corpus.
Looking at the prevalence of motifs in the Key Players' graph, it is striking how much these four works don't have in common. More than half of the motifs only appear in one book out of the four (as seen by the number of light green squares); since they don't share that many motifs, it seems to indicate each book's originality in comparison to the others. By contrast, the smoother color gradiant of the corpus graph shows that the motifs of the general corpus overlap more between the larger population of books as they influence and borrow story elements from each other.
Publishers: It would not be surprising to find out that William Lane and A.K. Newman specialized in publishing Gothic works. William Lane established the Minerva Press publishing house in 1790, where he was later joined and succeeded after his death by A.K. Newman. Other publishers in this graph may appear smaller only because they were more generalist publishers: Longman's company (seen here in various combinations of "Longman, Rees, Orme, Brown & Green") still exists today, as Pearson Longman, a well-known textbook publisher.
For another view of this data, see the maps page.
Trends in Motifs: This graph is another attempt to illustrate the prevalence of motifs, this time viewed through a temporal lens. The list of motifs are arranged in order of descending prevalence - essentially the same order in which they appear in the treemap chart above. At the same time, the frequency in which the motifs occur is indicated by the color gradient: the darker the color, the more books were published in a given year featuring that specific motif.
The key players' graph just shows where our four novels appear among this arrangement. I unfortunately couldn't figure out how to layer the Key Players on top of the corpus without losing the color gradient - if darker patches of color appeared after a Key Player, that might indicate some of the influence one work had over later works.