"The lungs of a ship": Ventilation, acclimatization, and labor in the maritime environment, 1740-1800.

This article examines the connection between projects for shipboard ventilation and the shifting medical discourse about acclimatization in the British Empire during the eighteenth century. I argue that the design, use, and disuse of a class of shipboard "ventilators" proposed by natural philosopher Stephen Hales helps us to trace changing ideas about the ability of European bodies to acclimate, or "season," to tropical environments. These ventilating machines appealed to British administrators because they represented an embodiment of providential and enlightened ideas that validated the expansion of overseas empire. In addition, they promised to increase labor efficiency by reducing the mortality and misery experienced by the sailors and enslaved people during long sea voyages. As skepticism about acclimatization grew in response to stubbornly high mortality rates in the West Indies, Hales' ventilators fell out of favor - a development underscored by their dismissal as a potential solution for the appalling conditions found in the transatlantic slave trade. By examining ventilators' nearly fifty-year career in naval and slave ships, this article will show the role of technology and the shipboard environment in the transition from enlightened optimism about acclimatization toward later attitudes of racial and environmental essentialism.