Scholars have worked for years to bring the life of Abraham Lincoln into sharper resolution. Michael Rogers thinks he can get it within five millimeters.
The professor of physics and astronomy at Ithaca College is spending a week measuring every bit — and byte — of Lincoln’s summer cottage in Northwest Washington with a 3-D laser scanner. When he and his team of two undergraduates are done, the place where Lincoln sweated out three D.C. summers and signed the Emancipation Proclamation will take on a virtual new life.
Preservationists and researchers will be able explore an ultra-high-resolution image of the structure — floor to ceiling, inside and out — exact to two-tenths of an inch. Students a world away soon may be able to “fly” through the room where Lincoln freed the slaves. If they wanted to, they could turn the house upside down and make it spin in space with the click of a mouse.
Similar scans of the Washington Monument and Lincoln Memorial have been done by other teams, as part of a growing trend of imaging historic and cultural sites around the world. In some cases, the scans have helped solve structural mysteries. They also provide a valuable record of current conditions that can guide future restoration and repairs.
Cottage officials said they don’t know yet exactly what uses they will make of this 21st-century take on the 19th-century structure, which is being done at Ithaca College’s expense.
“As historic sites go, we’re still brand new,” said Callie Hawkins of the National Trust for Historic Preservation, the group that led a seven-year, $17 million restoration of the Gothic Revival house and operates it as a public museum. “There’s so much that we’re still uncovering.”
Hawkins watched as Rogers and his crew set up the $95,000 device in a second-floor room on Friday. The Leica-made scanner, which looks like a sewing machine perched atop a surveyor’s tripod, throws out 50,000 laser pulses per second as the machine rotates. Timing how long it takes each light-speed blip to bounce back provides a precise measurement of the dimensions and shape of whatever is doing the reflecting.
“What you can learn is in the details,” Rogers said. After the scanning, he will process the data into a “point cloud” that can be displayed and manipulated as a 3-D form.
Sometimes, analyzing the images can expose spaces not apparent to the naked eye. Scans have led researchers to secret rooms used to hide runaway slaves in houses of the Underground Railroad, Rogers said.
“We’re not expecting any major surprises [at the Lincoln cottage], but you never know,” he said.
The team is scanning every room, negotiating the cramped stairs to the attic and aiming the laser around the air ducts crammed inside the basement. When the weather warms (the device can’t operate in below-freezing temperatures) they will scan the exterior of the 1840s-era house that sits on the grounds of the Soldiers’ Home off North Capitol Street.
The technology, developed to make renderings of nuclear power plants and other complex construction, increasingly is being used to document much older structures. (In some jurisdictions, police are using the device to capture crime-scene detail.) The television series “Time Scanners” has shown scans being made at the pyramids of Egypt and St. Paul’s Cathedral in London.
“At this point, it’s really becoming standard at all kinds of historic and cultural sites,” said Elizabeth Lee, a vice president of CyArk, a California-based nonprofit organization that is scanning high-value buildings and ruins around the world.
The group was founded by one of the inventors of the technology shortly after Taliban fighters dynamited the giant Buddha statues in Afghanistan’s Bamiyan Valley in 2001. CyArk’s mission is to enshrine world heritage treasures in digital relief and, to date, the group has scanned sites in more than 20 countries, from Mexico’s Chichen Itza to Mount Rushmore.
“The idea is to create an exact record of what’s there,” Lee said. “There have never been blueprints for most of these places.”
At the Lincoln cottage, officials hope to use the renderings to guide coming restorations. They hope to repair water damage in the vestibule, where William Slade, Lincoln’s African American valet, would have taken the president’s hat after his 35-minute horse ride from the White House. They’d like to restore the wood-and-iron veranda where Lincoln played checkers with son Tad and with residents of the Soldiers’ Home.
After an earthquake in 2011, employees couldn’t determine whether the quake had caused certain plaster cracks and crooked windows. Now they will have precise images to consult.
“It’s the level of data that we’re going to have at our disposal that we’re really looking forward to,” said Erin Carlson Mast, the chief executive of the Lincoln cottage. “We’re always looking for another degree of detail.”