Boston, MA

Massachusetts State House Time Capsule


On 4 July 1795, Samuel Adams, Paul Revere, and William Scollay led the procession from the old Massachusetts State House to the site of the new State House to lay the granite cornerstone.  In the excavated soil below the cornerstone, they placed a leather-wrapped package containing coins and an engraved silver plate.  This time capsule was discovered during foundation repair work in 1855, at which time the items were repackaged and additional items were added to the collection.  As part of an ongoing water-infiltration study, SGH led the consultant team that located and removed the time capsule after DCAMM raised concerns about the integrity of the artifacts.

SGH has been working with the Commonwealth on the State House for decades, providing structural, building enclosure, and material testing services.  Our work encompassed restoration and rehabilitation work on the historic facades, roofs, and interior spaces, including the Senate and House Chambers.
For the time capsule recovery, SGH’s work included the following:

  • Used non-destructive ground penetrating radar to locate the embedded time capsule
  • Designed the shoring to remain in place during the six-month examination of the artifacts and specified temporary weather protection that would not permanently affect the facade
  • Monitored the facade for possible movement during removal of the stones and subsequently while stones were removed and shoring was in place
  • Developed a stone removal procedure, which required the granite stones to be lifted vertically to avoid damage to the artifacts
  • Collaborated with volunteers from Boston’s Museum of Fine Arts to evaluate and conserve the condition of the artifacts
  • Advised on technical aspects of the new time capsule construction and placement

Project Summary



Completion Date
Building Enclosures
Massachusetts Division of Capital Asset Management and Maintenance (DCAMM)
Specialized Capabilities
Condition Assessments | Preservation

Key team members

Susan  Knack-Brown
Susan Knack-Brown
Building Technology Division Head, Boston
Dominic  Kelly
Dominic Kelly
Senior Principal