It was late on the afternoon of November 4th, 1875.  A party of men worked feverishly in dense fog and deepening Adirondack frost, chiseling into the hard summit stone of Mount Marcy, New York’s highest point. They had been working since the first hint of daylight without the benefit of food or water, pressing on to finish their work as conditions worsened.  They turned their attention to setting a benchmark – chipping into anorthosite so tough that it had destroyed scores of their drill bits and chisel points.

Their leader Verplanck Colvin had just completed the final rod and level measurement in a series that had begun weeks before, many miles away on the shore of Lake Champlain. At last the height of the mightiest peak in the Empire State was determined with accuracy: 5344.311 feet above mean tide.

The benchmark they laid on Marcy in the growing darkness and cold that afternoon was number 111 in a long sequence rising from Westport.

In the early fall of 2013 a young man named Kyle Kristiansen went metal detecting in the small town of Allamuchy, New Jersey.  Kyle has amassed an interesting collection of artifacts from American history. He began the day by detecting in his cousin’s backyard. He thoroughly swept the area before deciding to try a new spot. “There aren’t a whole lot of properties in the little town,” says Kyle, “only about 20-35 houses I would say. So I picked one that had an old look to it.”

An Adirondack Artifact

After obtaining permission, he went to work, waving his detector back and forth along the rows and sections he had laid out. After four hours his patience was rewarded with a high-pitched signal – a strong target. Digging three or four inches under the soil he found a heavy round metal object with a central stem, about two inches in diameter. It was quite corroded. Whatever it might be was impossible to tell, but it had lettering along the edges.

Only a couple of letters could be made out, and four numbers: 1882. He put it in his pouch, brought it home and added it to his collection, another unidentified curio among many.

For several months the disc-shaped object remained in Kyle’s collection pretty much in the state in which he’d found it. He had rinsed it off with soap and water, but not knowing its value and not wanting to damage it, he elected not clean it with chemicals.

Kyle’s curiosity at the strange nature of the disc with its obscured lettering and numbering finally got the better of him, however. He soaked the disk in vinegar, a mild acid that will remove corrosion. Over several cycles of soaking following by careful light scrubbing with tin foil, he saw the letters begin to emerge with more clarity. He took a few high-resolution photos under different lighting and found a contrast that amplified the etched characters – at last the complete writing emerged.

On the left-center of the disc were two small triangles, one smaller than the other and slightly offset, followed by the letters STA. On the right-center portion of the disc NO. 77 was engraved. Circling the disk, engraved along the edge, were these words: S.N.Y. ADIRONDACK SURVEY: VERPLANCK COLVIN SUPT. 1882

The nature of the etching and the year suggested that it might be historical and valuable. But Kyle had no idea what it might be. So like all enterprising young people, he Googled it. His web search of the etched text produced a link to the Adirondack Almanack (where else?).  Kyle made contact with Almanack editor John Warren who passed the story on to me.

I recognized the disc as a permanent benchmark placed by Colvin or a member of his crew during his landmark, decades-long survey of the Adirondacks.  It was essentially the same as the Colvin survey markers that can be found to this day on the summits of some Adirondack peaks.  Therefore it was likely an important piece of Adirondack history, wrenched from its rightful place at some point in the past.

I explained the marker’s significance to Kyle and explained that as an official survey marker it remained the property of New York State.  I asked him to send it to me so that I could research it and return it to the appropriate authority.  I sent him a prepaid shipping box and a book about Colvin and to his estimable credit he promptly mailed it to me.

I opened the box with excitement and examined the contents.  It was a Colvin benchmark, that was for sure.  It was a highly-corroded nickel-plated copper bolt with a stem that Colvin’s crew had sunk into a hole drilled into rock.  The stem was bent well off-center as though someone had exerted considerable force in order to pry it free.  The lettering was still hard to read but the station number, No. 77, was crystal clear.  I wrote a couple of experts who know far more about Colvin than I do and attached the Kyle’s high-resolution photo.  Their opinions confirmed my own.

Colvin and crew established thousands of benchmarks in the Adirondacks using a variety of techniques: chain survey, rod and level, barometer and chronometer.  But the cornerstone of Colvin’s work was triangulation: establishing a network of triangles, beginning from the shore of Lake Champlain and extending into the mountains using theodolite and transit, that ultimately mapped the entire region.

Of the thousands of benchmarks Colvin placed, only a few hundred of the most important ones were memorialized with copper bolts.  Kyle’s benchmark with its engraved triangles was clearly a triangulation bolt, one of the critical permanent markers anchoring Colvin’s entire survey.

I set out to find where in the Adirondacks it had actually been located and how it had ended up in a field in New Jersey.

Photo: Above, drawing of Colvin’s Rod and Level Determination of  the Elevation of Whiteface Mountain; and below, one of the photos Kyle sent to the Almanack of his object.