Analysis

Content Warning: This post contains subject matter that some may find sensitive or disturbing, be advised. If uncomfortable with this topic, you may support Death By Numbers in other posts. This post contains descriptions of bodies after a gunpowder explosion and fire. In January of 1649/50, the city of London was still reeling from almost a decade of civil war that had led to the beheading of King Charles I less than a year earlier.

We are in the process of checking the arithmetic of the Bills of Mortality, both its internal consistency as well as the accuracy of our work, and are making our Jupyter notebooks of our analysis public. The notebooks take into account transcription errors, printing mistakes, illegible data, or duplicate data to capture a comprehensive analysis of the data. Checking for duplicate transcriptions: This notebook analyzes duplicate transcriptions in the Bills of Mortality dataset to estimate the overall accuracy of our transcribed data.

Alongside quantitatively documenting plague outbreaks in Early Modern London, the Bills of Mortality also provide textual descriptions of causes of death. The Death by Numbers project is transcribing and making available to the public not only the plague numbers but also dozens of recorded causes of death found in the verso of the bills, which include accidents, killings, suicides, and drownings. This will eventually create a considerable –although not massive– corpus of textual data suitable for the application of several text analysis techniques, as a way to automate the extraction of information.

Following 1636’s outbreak, the plague cast a shadow over London’s life for almost ten years. Data collected from the Bills of Mortality by the Death By Numbers Project suggests that most summers witnessed a plague flare-up between 1638 and 1647. Though in the late 1630s these summer spikes were mild, the occurrence of the plague increased in intensity in the early 1640s up to 1647.1 Indeed, each summer during the 1640s, weekly deaths in London consistently reached into the hundreds, peaking at 250 in the years 1646 and 1647.

On Wednesday August 30, 1665, the diarist Samuel Pepys ran into his parish clerk and asked how the plague was progressing within their parish. To his dismay, the clerk “told me it encreases much, and much in our parish.” Worst of all, the clerk admitted that the plague was so bad that he had falsified his weekly reports of parish plague deaths: “for, says he, there died nine this week, though I have returned but six.

Death on Two Legs: Analyzing the initial 20 weeks of the 1636 London plague outbreak using time-to-event analysis. During the seventeenth century, England experienced multiple plague outbreaks. Although milder than the 1603 and 1624 plague crisis, London’s outbreak of 1636 claimed the lives of roughly 10,400 individuals, approximately 7.5% of the population in London and its liberties.1 In this blog post, I delve into the first stages of the 1636 outbreak, by scrutinizing the propagation of the plague through London’s city subdivisions, with the aid of time-to-event analysis.

The Bills of Mortality were weekly reports that recorded the number of deaths in London, beginning in 1603 and continuing consistently until 1819. These bills reported the number of burials and plague deaths in each London and surrounding parish. They also reported the different causes of death, male/female christenings, and male/female burials for the entire city. The causes of death included illnesses and ailments, as well as accidents and killings. Two causes of death—execution and murder—have the possibility of being cross-referenced with other early modern documents, particularly court records.

During the early modern period, the city of London produced weekly mortality reports called bills of mortality. These bills—printed from 1603 onward—detail the number of deaths per parish; plague deaths per parish; and deaths citywide by cause of death. However printed bills were actually summaries of manuscript bills produced for the monarch, which contain a parish-by-parish breakdown of every cause of death throughout the city of London for the preceding week.

During the early modern period, the city of London produced weekly mortality reports called bills of mortality. These bills—printed from 1603 onward—detail the number of deaths per parish; plague deaths per parish; and deaths citywide by cause of death. However printed bills were actually summaries of manuscript bills produced for the monarch, which contain a parish-by-parish breakdown of every cause of death throughout the city of London for the preceding week.

Samuel Pepys is primarily remembered for his decade-long diary, which recorded major events in 17th century English history including the Great Plague Outbreak (1665).1 Just before the height of the plague, on September 7, 1665, Pepys wrote in his diary, “[I] sent for the Weekely Bill, and find 8,252 dead in all, and of them 6,878 of the plague; which is a most dreadfull number, and shows reason to fear the plague hath got that hold that it will yet continue among us.