"The fact that it was a failure is what saved it," said Richard Hart Vara, author of a new book on the mill that sets forth a theory of how it operated.
"The Dover Union Iron Mill," which Vara not only researched and wrote but also laid out on his home computer, uses archeological records, historical accounts, and original mathematical calculations based on artifacts to unlock secrets that have lain hidden since not long after the "rolling and slitting" mill went out of business about 170 years ago.
The site of the old mill, which has been partially reconstructed, is well known in Dover, where it straddles a popular conservation trail 25 minutes' walking distance from a parking lot at town-owned Caryl Park off Dedham Street. It is within Noanet Woodlands, which is owned by The Trustees of the Reservations, a nonprofit conservation group.
But while it is a destination for hikers and picnickers, Vara noted that most visitors probably do not know much about it, since there are no signs that describe what it was.
According to Vara's account, the mill was built about 1815 to harness the power of the Noanet Brook to turn bars of iron into barrel hoops and plates, from which nails could be cut. It was funded by investors from Dover, Medfield, Newton, and Boston.
To maximize the power from an unreliable water supply, the mill was centered around a massive wooden waterwheel some 36 feet in diameter. Present-day visitors can get an understated view of how big that is by standing downhill from the dam and looking up at the stone wall, then walking upstream to the former wheelpit.
Water flowed into the waterwheel's buckets -- 108 of them -- which caused the wheel to turn, powering machines that rolled the heated iron into sheets and cut them into usable sections. To keep the wheel turning, the company built ponds upstream for a water supply and regulated the flow of water in the brook.
But by 1828, the directors of the company began selling off land, and the mill seems to have ceased operations altogether about 1832.
The traditional view in Dover is that the iron mill failed because the flow of water in Noanet Brook was not dependable. Vara accepts that hypothesis, but he also theorizes that the rise of steam engines might have rendered the backwoods mill obsolete.
Yet while the iron mill has been a part of Dover lore ever since it was built, for more than a century no one could claim an intimate understanding of how exactly it worked -- not even Roland Wells Robbins (1907-1989), an archeologist who excavated the site and reconstructed part of the dam in 1954.
But Vara, using Robbins's careful records and artifacts he unearthed (such as metal gearing teeth), was able to figure out the whole thing, even down to the rotations per minute of the interconnected wheels and the horsepower the mill was able to generate.
"I feel like it's pretty complete," Vara said.
The result, say several experts in the field, is a useful contribution to the study of American industry.
Technically, Vara, 75, a retired engineer and architect, is an amateur at this sort of thing. But his book is getting serious attention from scholars.
Don Linebaugh, associate professor of anthropology at the University of Kentucky and director of the university's Program for Archaeological Research, praised Vara's work as a convincing interpretation of an unusually well-preserved 19th-century mill site. In an interview, Linebaugh said he would consider using Vara's book as a textbook for a class on industrial archeology, as a useful case study.
"I think he's done a fantastic job," Linebaugh said.
Curtis White, park ranger at Saugus Iron Works National Historic Site, where colonists produced iron products in the mid-17th century, said Vara's work makes for useful comparisons between the Dover Union Iron Mill and similar operations elsewhere.
In an interview, White noted that mill sites that did not operate very long -- like Dover's -- offer an unusual perspective on what the state of the art was at a particular time.
"Archeologically, it's like a time capsule," White said.
Vara, who grew up in Needham, moved to Dover in the 1950s and has lived there ever since. He said his book began as a means of providing calculations for a model a former Dover resident was looking to construct.
Stan Adams, a 39-year-old Norwood resident who grew up in Dover, wanted to build a miniature of the old iron mill. "It's such a treasure of Dover," he said in an interview. "I think it makes it a really special town."
In the beginning, Vara had no hope of compiling details about the mill, but just wanted to offer a broad overview of its major parts so he could offer a design with measurements to Adams.
Eventually, he believes he compiled enough information to explain the whole operation.
In doing so, said Paul Tedesco, president of the Dover Historical Society, Vara has recreated a vital part of Dover's history.
"Vara's achievement," Tedesco said, "is that he took something that was important for this community, even though it failed, and he was able through his own perseverance and searching to figure out what it looked like and how it worked and what its potential was if everything went right."
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