CHARLOTTESVILLE, Va. (AP) — Doug Harnsberger first saw the sketch in 2012 while searching through Thomas Jefferson's papers: a thumbnail drawing of a circle with spokes radiating outwards.

For 200 years, the sketch was mislabeled as a skylight at the University of Virginia's Rotunda. But Harnsberger had written his thesis on an architectural style of roofs known as Delorme domes. The sketch was the first plans for the Rotunda's dome, he realized, setting off a yearslong effort to recreate Jefferson's original vision.

"It's just a beautiful, simple design," he said. "It was in use in Europe for hundreds of years. Then Jefferson brought it to America, and for 25 years, every dome was made this way."

Even more, Harnsberger realized, the first sketches envisioned the inside of the dome as a planetarium, not its eventual and current use as a library. A professor could be hoisted aloft on a pulley system and use chalk to sketch the movements of the stars.

The use changed, but the construction plan remained. And for a century — until the Rotunda burned in 1895 — Jefferson's ingenious design held up the dome. Now, Harnsberger and a team of professors and students at UVa's School of Architecture are working to replicate the original plans and, in the process, learn and teach his techniques.

"We're trying to celebrate the original Rotunda," Harnsberger said. "No one has seen it in living memory, really. Not since it burned."

The design is based upon ideas from 16th-century architect Philip Delorme. Historic preservationist Tim Robinson cut and milled thin, curved slices of white oak and then fit them together to create a long rib. Each rib rises to meet an oculus at the top of the dome. Though each piece weighs hundreds of pounds, a "pair of untrained carpenters," as Jefferson put it, could put one together with careful planning, grooved joints and plenty of nails.

Jefferson became enamored with domed buildings during a 1786 trip to France and, when he returned to Virginia, brought the concepts with him. Eventually, he saw Delorme domes built in Richmond, Philadelphia, Boston and Baltimore. The technique was a fire hazard, though, and some famous Delorme domes, such as the U.S. Capitol's original low wooden dome, later were replaced with cast iron. The Rotunda was rebuilt after the fire with different methods.

In 2016, Harnsberger and Ben Hays, a UVa lecturer in the architecture school, helped a History of American Building Technology class create a 1:10 model.

"There's a lot to be learned from doing things by hand," Hays said. "You can see it in a drawing and look at it in the field, but that's not the same thing as actually doing it."

The current project, though, was on a 1:3 scale and was much more challenging to build, Hays said. Dietlinde Maazel, the owner of Castleton Farm in Rappahannock County, and UVa's Bicentennial Comittee funded the project.

Tabitha Sabky, a master's student who took Hays' class this spring, said she hoped the project would encourage students and passers-by to think about the architectural planning of the Academical Village.

"I don't think people really engage with the structures at UVa," Sabky said. "They associate the university and Jefferson with columns and classicism and don't realize he was an architect, and they also don't realize the amount of effort and planning that went into each of these buildings."

Jefferson was never trained as an architect, and he intended the Academical Village to serve as a learning laboratory for students, according to a recent exhibit at UVa's Fralin Museum of Art. Each building demonstrated a different technique or style. For neoclassicism, the Rotunda's Dome would have been the highlight of architectural achievement.

"The conservators and architects have done a fantastic job of recreating the known elements in the recent restoration," said Harnsberger. "What I'm interested in is the architectural ideal and what Jefferson's aspirations were."

The dome project may correct misconceptions and help Jefferson scholars understand his vision and process, said Tim Robinson, a historic preservationist.

"In all the restorations, you have to retain the stories," Robinson said. "If you lose the buildings, you lose the stories. A part of it was lost in 1895; we just want to bring it back."

The replica will be displayed on the Lawn between June 11 and June 25. After that, it will have a new mission: as a focal point for weddings and events at Castleton Farm.