Old Ponton Bridge at N. McGregor, Ia. 1885

"Old Ponton Bridge at N. McGregor, Ia." is a cyanotype print created by Henry P. Bosse in 1885. The image depicts a wooden bridge crossing a river, possibly the Mississippi. The bridge is made of pontoons, which are floating supports, and is a type of temporary bridge. The cyanotype process, also known as "blueprint," creates a monochrome image in shades of blue. The image is framed by an oval shape, which is a common technique in 19th-century photography. This print is part of the collection of the Metropolitan Museum of Art in New York City.