The world might be excited by that metal obelisk that disappeared shortly after it was found in the Arizona desert, but New Hampshire has its own obelisk that has made an unexplained appearance on a ridgeline about a mile south of Mount Sunapee.
This obelisk is a three-sided stone – maybe it’s granite, but I’m not certain – shaped like a prism and a little over 2 feet long, standing upright in the middle of a pile of big rocks with a stone cap on top. Each of the three sides has a small triangle carved into it and painted yellow. Nearby is a rusting yellow metal marker nailed to a tree, like a blaze marking a side trail. Except there’s no side trail to mark.
My wife and I encountered this surprising object last weekend while hiking the Monadnock-Sunapee Greenway Trail. It looked significant but it wasn’t clear what was being signified.
It doesn’t alert hikers to any deviation in the path, which runs straight in both directions, or to any nearby feature. It is located atop a peak but it’s a minor peak with absolutely no view. Certainly not worth so much fanfare.
Puzzled, I took a cell-phone photo and sent it to the Monadnock-Sunapee Greenway Trail Club, the volunteer group maintains the 50-mile hiking trail. The email response came from Dan Read of Marlow, a longtime MSGTC volunteer.
He said the rocks had been there as long as he knows, but were scattered until recently.
“That cairn has been recently rebuilt to its present condition. We don’t know by who,” Dan wrote. (I told you it was a mystery.) “It has prompted lots of inquiries, the first of which started coming in around late August.”
However, Dan does know why the stone existed in the first place. This is the fun part.
“The original purpose is as a (U.S. Geological Survey) benchmark. . . . We’re thinking of putting up a sign that reads: ‘This very point of New Hampshire was first established in 1872 and monumented/benchmarked and described in 1873. It was part of the United States Coast & Geodetic Survey program to accurately map the United States. Think about it, over 140 years ago, surveyors stood here with a transit turning angles to triangulate between benchmarks, to measure and map the hills and valleys you see before you.’ ”
Regular readers of Granite Geek will have perked up at that description, recognizing a project that I wrote about two years ago after I stumbled across mention of it carved into rocks atop Mount Kearsarge.
The story began in 1839, when New Hampshire Gov. John Page signed “an act to provide for the geological and minerological survey of the state,” Dartmouth geography professor Elihu T. Quimby (they don’t make names like that any more) got the contract to do the mapping for the government agency that was the predecessor to the Geological Survey.
With help from students and assistants starting in the 1860s, Quimby went atop various mountains in the state and erected a 15-foot pole painted black and white, and topped by a nail keg painted black. This contraption was visible from scores of miles away. That’s especially the case where there were few trees to block the view – Southern New Hampshire’s forests had been cleared to create pasture during a sheep-shearing boom. (Which turned into a bust when wool prices plummeted, but that’s an economics story rather than a scientific one.)
Quimby’s team spent several years going from one mountaintop to another, sighting distant black nail kegs through a theodolite, the device used by surveyors to accurately measure angles. They used the resulting figures to create the first accurate statewide map through triangulation.
Triangulation uses little more than simple high school geometry to accurately determine distant locations (remember the “angle-side-angle theory”?) but it remains the standard method today.
Among the mountaintops that Quimby summited with his equipment were such notables as Washington, Monadnock, Kearsarge and Cardigan, lesser-knowns like Uncanoonuk and Whiteface – and this one, which doesn’t seem to have a name any more. It must have had pretty good views when it was treeless, or else Quimby would have used one of the peaks of Sunapee, which is much taller.
I don’t know if the obelisk was put there by Quimby or somebody else later on – it appears to have been quarried, and carrying it up two miles of trail from the town of Newbury would have been a major chore – but I’m delighted that some anonymous folk have set it back up.
If you want to learn more about Quimby’s project, head to the state archives in Concord. They have all of his teams’ notebooks, which are full of data written in 19th-century copperplate script. Hundreds of measurements are included in dozens of books because Quimby didn’t measure just from mountain to mountain but also took angular measurements of any prominent object he could see to help fill out the maps. That includes “the ridgepole of big barn” at Shaker Village in Canterbury and the “gold ball atop dome” of the State House.
(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)
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