Builders left a mark on historic Shrewsbury mansion

Or is it just a leg-pull and the spirit of a long-dead carpenter is today howling with laughter at our modern bewilderment?

One of Shrewsbury's medieval gems has been yielding some of its secrets during work to turn the Shrewsbury Music Hall complex into a museum and art gallery.

The most unpleasant discovery at the 13th century Vaughan's Mansion is that past alterations were a mix of bashing and bodging – so badly bodged in fact as to weaken and imperil the structure. Securing it has taken six tonnes of steel.

And then there's the dead fish. Between the joists, a worker found a makeshift box apparently knocked up by a carpenter of long ago.

Inside was something wrapped in paper – the backbone of a fish.

Close inspection revealed an inscription on the inside of the box: "Dear friends, here lie the remains…" and the rest is obscured.

Other voices from the past were discovered by accident on a floorboard on which carpenters of yesteryear left a "we wuz here"-style message.

"As it was being placed in the stores it was turned over, and then it was realised that there was a lot of writing on it," said project manager John McStay of construction firm ISG.

The discoveries were made in a part of the building which dates to 1623, although the indications are that they are much more recent.

While the inscription has yet to be fully deciphered from the aged and stained wood, it makes a reference to Shropshire Yeomanry Cavalry, which would mean the time of the Napoleonic Wars would be the earliest possible date.

"There's a mention of having a nightcap, and it talks about the carpenters being 'a set of very fine young men,'" said Mr McStay. It also gives the carpenters' names and ages, mentions that the floor was done at the expense of "Mr Jobson now liveing at the Talbot Inn" and mentions with no doubt approval "1 pint of small bevi a day allowd us".

These finds are, says Shrewsbury Museums manager Tim Jenkins, all part of the story of the structure.

Largely obscured from public view for over 100 years, Vaughan's Mansion is emerging at last as a building in its own right from the shadow of the Music Hall.

While the Music Hall, which dates from 1838, is often referred to as one building, the complex actually swallowed up various structures with a mish-mash of styles and features from building periods stretching back over 700 years.

Among the more unusual features are police cells and a nuclear war command centre with concrete walls a metre thick.

The work has involved peeling back layers of history at Vaughan's Mansion to reveal its medieval core. The process has also uncovered various horrors in the way the building was altered over the years – a floor which was suspended rather than supported, removal of vital roof braces, and enlarging a doorway by cutting away pillars from the bottom, so they simply hang.

"I don't think anybody was expecting to find the level of structural difficulty we encountered. The work has really been to save the structure. Our challenge was to conserve as much as possible and also make Vaughan's Mansion structurally sound.