Dendrochronology Study

February 2015Scientists at the University of Oxford have used state-of-the-art methods to determine the age of the Hyland House Museum in Guilford, Connecticut. Analyzing tree rings extracted from house timbers, the scientists have determined that the house was built in 1713 from ancient white oaks. The oldest wood in the Hyland House comes from a tree that was alive when Columbus arrived in the New World in 1492.

The Hyland House has always been known to be one of the oldest buildings in Guilford, but no one knew exactly when it was built. Documentary evidence, including family histories, account books, and land records, suggested that it was built in the seventeenth-century, but details in the house’s structure suggested a date in the mid-1700s.

In 2014, Hyland House Museum curator Sandra Flatow invited University of Oxford archaeologist Daniel Miles to study the house. Dr. Miles is an expert on dendrochronology, the science of measuring the age of trees based on the number and size of their rings. A tree will form a new growth ring each year. The width of the ring will vary based on the tree species, the amount of rainfall, and other factors.

Dr. Miles is the head of the Oxford Dendrochronology Laboratory, which has dated more than 900 buildings over the course of three decades. In England, they have dated the Tower of London and Westminster Abbey. In the United States, they have been commissioned to study more than one hundred buildings, including George Washington’s home at Mount Vernon.

In November 2014, Dr. Miles and his colleagues came to Guilford and took samples from the Hyland House. They used a hollow augur to extract ten half-inch-wide cores from the sills, summer beams, chimney ties, and rafters. Miles brought the cores back to the lab in England, where the cores were cleaned, sanded, and polished. He then analyzed the tree ring patterns with a computer, and found that seven of the trees matched patterns of New England trees from the same period.

Dr. Miles and his colleagues discovered that two timbers came from trees felled in the spring of 1712, while the remaining timbers were all felled in the winter of 1712-13. “Because most early buildings were built with green timbers, this would strongly suggest a construction date of 1713,” said Dr. Miles. The full dendrochronology study can be read here.

And how does the Hyland House feel about its birthday?

We are delighted that science provided us with a rigorous way to date the house. This research give us yet another story to share with our visitors. Our mission has always been to connect our community to Guilford’s rich colonial history. The more we know about that history–and how history is reconstructed–the more interesting that story becomes.