Three months ago that letter was found and now the school is ready to continue the legacy with a message of its own.
Contractors found the letter when they began reinforcement renovations on the archway.
Rector Richard Hall said it was a complete surprise.
It was with a specialist who was determining the best way to preserve the artefact.
The new time capsule will be installed just before the renovations are complete.
Inside the airtight PVC pipe are an academic blues award, school badges and other pieces of modern history.
He said there was more to life than just Covid-19, so the contents steered clear of the topic and instead offered a positive outlook on the present day.
The wooden seals for the capsule were designed by the woodwork department and featured the school crest and the year.
The renovations were necessary to keep the archway in good condition.
The memorial had sunk and warped over recent years as a result of traffic strain.
‘‘It was never designed to handle anything other than foot traffic,’’ Mr Hall said.
The original material had been carefully removed and would be reinstalled once the reinforcement was complete.
The archway would look the same as before, but ‘‘a little cleaner’’.
It had taken about three months, but the work would hopefully be done soon, he said.
The time capsule would be sealed safely inside the archway. However, he planned to organise a message with details to be put somewhere at the school so future generations knew it was there.
