Dendrochronology Work at the Shepherd Barn-2Dendrochronology Work at the Shepherd Barn,
Historic Northampton 2016
Submitted By Laurie Sanders
February 13, 2017
Overview
Historic Northampton’s campus includes four historic
structures—three former homes and a single outbuilding. While the dates of the construction of the houses have been well-researched and documented, the age of the barn has been less
certain. Previous research at the Registry of Deeds has not pinpointed its date of construction, and over the years there has been a debate as to whether it was built in the 18th or
19th centuries.
Knowing exactly when the outbuilding was constructed is valuable to Historic Northampton for several reasons. For one, the date of the barn helps inform our decisions
about the building’s much-needed repairs and renovations. Secondly 18th century and early 19th-century barns are rare in Northampton and the Connecticut River Valley. Finally, understanding
the age of the timbers and their identification helps give us more information about the local surroundings and broadens the conversations we can have about climate change—past and present.
Project
To determine the age of the barn, we hired William Flynt, an expert on dendrochronology and an architectural conservator at Historic Deerfield. He
visited Historic Northampton
in July 2016 and using a boring drill, collected 13 samples from selected timbers within the Shepherd Barn. The choice of timbers was made based on architectural position and the presence
of an outer-layer of bark. Bark helps pinpoint the precise year when the tree was cut and stopped growing. One of the other objectives when selecting where to drill is to choose
timbers where the borings will capture more than 50 years of growth.
After sampling was completed Flynt took the labeled borings to his lab where he sanded them, counted the rings
using magnification, and ultimately compared them to a library of samples that he has developed during the last 15 years. Because the width of the growth rings are influenced by climate,
they are like a fingerprint and can be compared and matched against samples with known dates.
With the aid of the computer program, Flynt was able to develop a “best fit” for each
of the samples and was able to determine the year the tree was felled.
Results from 2016
Of the 13 samples he collected, 12 were from pitch pine and 1 was from oak. Pitch pine was
the go-to building timber in our region in the 18th century, especially in Northampton, where large stands of pitch pine grew over the thin sandy soil that developed on glacial outwash
plains and glacial deltas. By the mid-19th century, however, most of the sizeable pitch pine had been cut in Northampton and construction framing shifted to hemlock.
Based on the best-fit
analysis of the samples, Flynt concluded that all of the pitch pine used in the barn’s framing had been cut in 1801 or 1802, which means that the earliest date of construction would
have been in 1803. That date, however, isn’t completely solid because the sample from the single oak indicates that it was cut in 1804. The presence of the oak means that either the
barn was constructed in 1805 or the oak timber was originally used in another structure and later re-used in the Shepherd Barn to replace a failing timber. The latter is the more likely
explanation.
Next Steps
Knowing that the barn was built within this very narrow, two-year window, we plan to review the tax records for this parcel from 1800 to 1806. It’s quite possible
that the records will reveal an additional tax when the new barn was built.
In addition, we will be able to supplement our knowledge of the barn’s uses and construction with the help
of some of the nation’s best timber framers. On April 1 the Shepherd Barn will be assessed, explored and evaluated by members of the North American Timber Framer’s Guild. Bill Flynt
will be on-hand and among other things, will point out the confounding oak timber. By looking at how the studs are mortised in the oak timber, the timber framers will be able to tell
if the studs could have only been installed originally or if the post could have been inserted later.
Time Line of Work Completed to Date:
July 2016: Bill Flynt visited and collected samples from 13 timbers
August: Flynt completes analysis
September 2016: Final dendrochronology report
submitted
Next Steps in 2017
Winter/Spring: Tax record analysis
April 2017: Visit by Timber Framer’s Guild
In our final report, we will provide a summary of what we learn from the
timber framers about the barn’s construction and its uses as well as what we are able to glean by researching old property tax records.
Expenses to Date
William Flynt, Consultant $1,300
Potential Uses of Remaining Funds ($1,000)
If acceptable, we would like to request permission from the CPC to use the remaining $1,000 to:
Grade the perimeter of the barn and add a
band of gravel so that the water drains away from the barn’s sills, joists and corner posts
Make repairs to the roof (if needed)
Organize a series of public programs related to the dendrochronology
and the Shepherd Barn. Presenters would include Bill Flynt, Jack Sobon (expert on New England barns), and Julie Brigham-Grette, a climatologist who will explain how data from historic
buildings and tree rings adds to our scientific understanding of climate change.