Jennifer L. Mass will give a Work-in-Progress talk on Monday, January 29, at 12:15 pm. Her talk is entitled “Reverse Engineering the Past to Secure a Future for the 1876 Dry Tortugas National Park Harbor Light.”

The Dry Tortugas is an island group in the Gulf of Mexico discovered by the Spanish in 1513. The seven keys that make up the Tortugas are extremely low-lying islands, and their associated coral reefs make navigating the strategically important waters surrounding these islands extremely dangerous. This led to the placement of a brick tower lighthouse on Garden Key in 1826. The original Garden Key lighthouse was badly damaged in a hurricane in 1873, and was replaced with the “boilerplate construction” Harbor Light in 1876. The National Park Service requested a conservation assessment of the Harbor Light in 2016 due to the structure’s accelerating rate of degradation. The goals of the assessment, which Mass was involved in, included: identifying the iron alloys of the Harbor Light; identifying any electrochemically incompatible materials (such as copper alloys) that might be contributing to the rapid decline of the Harbor Light, and characterizing the finish history/corrosion protection strategies applied to the structure throughout its lifetime. The ultimate outcome for this project is a conservation strategy consistent with the aggressively corrosive environment of a subtropical island in a hurricane zone.

Analysis of the structure revealed critical information about the technology of nineteenth-century wrought iron construction, including the history of twentieth-century preservation attempts for these acutely vulnerable structures. Wrought iron was an aesthetic and engineering marvel of the nineteenth century, used in both the 1837 Winter Palace in St. Petersburg and the monumental 1887 Eiffel tower. It also forms the delicate tracery seen in architectural ornament of the period, from scrolled and foliate gates, balconies, and fences to light fixtures and furniture. This project is the first attempt to document the history, alteration, and preservation strategies for a rare monumental wrought iron sheet structure.