(CNN) -- A time capsule buried by patriots Samuel Adams and Paul Revere more than two centuries ago was unearthed Thursday in Boston.
The box-shaped capsule was placed by the Revolutionary-era duo in a cornerstone of the Massachusetts State House in 1795, the year construction began on the building, CNN affiliate WBZ reported.
When current-day workers repairing a water leak found the hidden antique, they called in a local expert from the Museum of Fine Arts who spent the better part of Thursday delicately and painstakingly chipping away at the cornerstone trying to extricate it.
"What we know the box contains, based on the notes that we have, is a Paul Revere plate, papers, and coins from the 1600s," said Massachusetts Secretary of State William Galvin, who also heads the state's historical commission. "It may contain other stuff too, we don't know that yet," he said.
Galvin told CNN that the capsule's contents are expected to be revealed sometime next week. For now, it's getting some TLC and a thorough exam -- including X-rays -- by the museum's staff.
"The contents are of concern, but the plaster that held the box in place is in good condition," he said.
This is not the first time this particular capsule was unearthed, according to Galvin. In 1855 it was dug up during emergency repairs to the State House and put back in place when the cornerstone was reset.
Extra precautions were taken then to ensure the box's safekeeping.
"There were some coins that were tossed in the 1855 ceremony in the mix of the mortar. They are in good condition so we are optimistic that the box itself has withstood the test of time and that it will therefore be holding the contents securely," Galvin said.
Galvin says both time-capsule events -- in 1795 and in1855 -- were chronicled in detail, and said his office is looking into whether the box will be reinstated and whether new items from the current era will be added to the box and reburied.