The dates of old houses, says Ron McCauley, a vice president of the East Lyme Historical Society, can be a little like fish catch stories.

Some exaggeration can be involved.

The date of the Thomas Lee House, which the society has long estimated at 1660, making it the second oldest wood frame structure in the state open to the public, may soon be determined more exactly.

Just which way the new date may fall — earlier or later — is anyone's guess until the results from a new scientific analysis are in.

On Thursday, a project by the Oxford Dendrochronology Laboratory, which dates buildings around the world by analyzing tree rings of wood core samples, got underway.

Daniel Miles of Oxfordshire, England, a partner in the Oxford Dendrochronology Laboratory, whose dating projects have included such landmarks as Windsor Castle, the Tower of London and Mount Vernon, was on hand Thursday as core samples were being removed from the aged timbers of the Thomas Lee House.

These eventually will be analyzed under microscope back in the Oxford laboratory and compared to a growing database of others.

By comparing the nature of the annual tree rings in the Thomas Lee samples to other known dated core rings, the width indicating year-to-year growth changes due to factors like insect infestation or drought, should enable them to determine the year timber used to build the house was felled.

That would closely approximate the year the house was built, since houses in that time period were usually built with green, not aged, timber.

They expected to have about 30 samples, with some from each of the three general periods of construction of the house, by the end of Friday.

The dating analysis, if possible from the samples harvested, should then take a few months.

The Thomas Lee House project began with a chance visit to the house by Michael Cuba, president of the international Timber Framers Guild, who was visiting relatives and happened by while making a stop at the East Lyme Book Barn.

Cuba, who does a lot of work in the United States with Miles, eventually proposed a dating project to the East Lyme Historical Society.

On hand Thursday to help take the samples, Cuba called the Thomas Lee House a "gem" for its originality.

Indeed, the house is distinctive for its spare original features, having never been inhabited in the 20th century. It's never had plumbing or electricity, except a wire run in to operate a light or tool.

When the historical society acquired it in 1914, along with another house on the property and 100 acres, for $500, it was being used as a chicken coop and slated to be torn down.

It was opened to the public after a ceremony June 9, 1915, featuring former President William Howard Taft as a guest speaker. This is one of only a few events I've ever heard of, not related to submarines or the Coast Guard, to have brought a president to the region.

Both McCauley and John O'Neill, another society vice president, said the 1660 date used for the Thomas Lee House is based on a combination of historic records about the Lee family and analysis of building techniques and materials in the building.

But, until now, it has been largely informed guesswork.

Both also assured me the society is determined to follow the truth wherever it leads, even if it means they have to rewrite their own history a bit.

At the very least, the society might have to change the prominent 1660 date signs on the house.

"We are always trying to refine what we know," O'Neill said.

This is the opinion of David Collins.

d.collins@theday.com