Armel Cornu: “Ships and Worms: the History of France’s Copper Sheathing in the Eighteenth Century”

Abstract:

My paper retraces the history of copper sheathing throughout the French eighteenth century. As marine worms began to eat away at every submerged wood structure in the early 1700s, all manners of ships became highly vulnerable. In reaction to this unassuming yet most allarming crisis, a host of scientific practitioners, navy officials, entrepreneurs, and other interested parties began to pool their efforts to face the worm threat. These endeavours eventually led to the widespread adoption of copper sheathing: a way of cladding the hull of a ship in a thin sheet of copper, making it resistant to worms and faster at gliding through waters.

My paper tells the story of this unique technology, and speaks of its consequences for eighteenth-century war and trade. I explore the reasons why copper sheathing was implemented, its specific challenges, and the resulting economic ties for the French state, as the majority of the copper had to be imported from Sweden. The French revolution and subsequent trade breakdown upended France’s copper supply chain, forcing revolutionary savants to learn how to strip copper from any possible source, from stolen ships to church bells.

By examining the evolving role of scientific and technological knowledge in the recurring struggle of the French Empire to secure copper, my paper critically examines the creation of discourse surrounding the search for such minerals in the early modern period, outlining its political and colonial outcomes.