Since its installation atop Philadelphia’s City Hall in 1894, the bronze, 37-foot-tall statue of William Penn has served as one of the city’s most prominent landmarks. However, the airborne pollutants in the statue’s urban environment gradually caused advanced corrosion of its exterior. Moorland Studios, helmed by metal conservationists Constance Bassett and David Cann, stepped in with a bold, innovative preservation proposal in 1987. In the decades since, they have completed four treatments of the statue, most recently in July. We spoke with the pair about the project and their overall approach to metal conservation.

Old with the New

Cann and Bassett’s million-dollar idea back in 1987 was to clean the surface of the statue using pressurized water, but recent restorations have embraced modern techniques, such as removing debris using lasers, instead. Says Cann: “From our point of view, in the conservation world, you have to use every tool in the box. And we like the new technology as much as using hand tools and hammers.”

Safety First

The biggest challenge was the 26.5-ton statue’s location, 550 feet above a busy city. This eliminated traditional methods of cleaning such as media blasting, which could endanger the pedestrians below. Using pressurized water and, later, laser technology alleviated these concerns, though snaking water lines to the top of City Hall proved to be a hassle in its own right.

Saved by the Bell

Although Cann and Bassett, who are based in Stockton, New Jersey, developed the preservation plan, the statue would not have been saved without local support. The city of Philadelphia lacked the funds to restore the statue in 1987, prompting concerned citizens to create the Free William Penn Campaign. It raised enough money to fully fund the first three restorations and part of the fourth. “We’re grateful that the city of Philadelphia cares. People from all walks of life really seem to care [about the statue],” says Bassett.