CONCORD, N.H. (AP) — Paper, the traditional gift for marking a couple’s first year of marriage, also is a great choice for 250th anniversaries — especially when filling a time capsule celebrating American independence.The 2016 law creating the nonpartisan America250 commission mandated that a time capsule be buried in Philadelphia on July 4, 2026, and dug up 250 years later in 2276. Last week, the resulting 900-pound cylinder was sealed shut, capping years of technical design and construction, collaboration with states and meticulous review of collected items. “Once it was closed, it was a little bit anti-climactic, and then it was kind of really emotional,” said Michael Berilla, who directs the fabrication technology office at the National Institute of Standards and Technology and led the team that designed and built the capsule.
Designed to stay dryBerilla’s office, part of the Department of Commerce, has built encasements to protect historical documents in the past, but those tend to be stored indoors under carefully controlled conditions. With time capsules, the number one enemy is water, so much of the design work focused on how to keep it out.The stainless steel capsule is shaped like a cylinder, not the typical box, because square edges tend to crack and break. It will be covered with a secondary cylinder that will trap air and push out any approaching water, and the capsule itself is rimmed with a soft metal that compresses under pressure.
