The Chamberlain is the only surviving bridge of the original five. The others were replaced as the river rose due to flood control dams put in place over time.
"Some of New Hampshire's most aesthetically pleasing yet least appreciated structures are stone arch bridges."
"The majestic Forth Bridge ... symbolises the tremendous achievements of Victorian engineers and the immense strides made in the technique of bridge design and construction since the dawn of the Railway Age..."
- Derrick Bennett, Bridges: Great Buildings of the World
"Fink's truss design was one of a number of early patented solutions to [the problem of how] to carry a massive, moving weight (a train) over long spans (to avoid the expense of building piers and obstructing waterways) on easily erected bridges (often in rough terrain) with good long-term economy..."
- Kent Farnow Smith, "America's Oldest Functioning Iron-Truss Bridge," 1978
Designed by William A. Truesdell, a railroad engineer, the Seventh Street Improvement Arches celebrates the engineering application of mathematics to improve living conditions.