Magic lantern shows through a macroscopic lens: topic modelling and mapping as methods for media archaeology

This article explores trends across Lucerna, an online web resource for magic lantern materials, by combining two digital approaches: topic modelling and geospatial mapping. Topic modelling identifies words that occur most frequently together in a large corpus of texts through a form of statistical analysis. Using this method, I studied 2,000 descriptions of magic lantern shows given between 1874 and 1903. While there were records from Canada, India, and New Zealand in this data set, most of these lantern shows occurred in England. The groupings of words, or ‘topics’, reflected the prevalence of the Church Army, Band of Hope, and Sunday Schools in Lucerna’s textual record. Mapping these patterns revealed that descriptions of magic lantern shows were relatively uniform across the UK, suggesting that magic lantern shows in urban and rural spaces were represented similarly in periodical literature. Since the topics did not vary by region, I studied how the most prevalent topics differed by host organization and how they changed over time. The article finds that descriptions of lantern shows given by evangelistic organizations shared vocabulary with those hosted by Sunday Schools and temperance societies. It also shows that evangelistic shows tended to avoid the language of entertainment, echoing earlier discourse about the magic lantern on the mission field, and that the decline in topics related to Sunday Schools over time corresponds with the rise of educational lantern lectures, particularly those given by secular institutions like the Royal Albert Memorial Museum in Exeter. Overall, the article suggests that topic modelling can be used to excavate the performance history of lantern shows by foregrounding latent linguistic similarities in published descriptions of these events.