The panorama was photographed using the wet-plate process. This had replaced the Daguerreotype because any number of prints could be made from the negative plate. Daguerre’s process (the first practical photographic technique) produced only a positive print, which could not be copied.

The wet-plate process required a portable darkroom for any outdoor photography because if the plate dried between exposure and development, it was ruined. Duryea must have taken his darkroom with him up the Town Hall tower so that he could develop each picture as soon as it was exposed. It must have been a nerve-racking process.