Prisoners at historic Port Arthur were not allowed to carry money. So how did a pile of silver shillings worth about a week's salary for one of the penal colony's overseers end up buried beneath the convicts' workshop?
"It's such an evocative find, it's so out of place," said Port Arthur Historic Site Management Authority conservation project officer Sylvana Szydzik.
"We know that convicts occasionally had coins, but that was a pretty substantial amount of money at the time."
The coins were found during a 10-month archaeological dig of the foundry and blacksmith site conducted by University of New England post-doctoral research fellow Richard Tuffin and Ms Szydzik.
The find joins other discoveries such as handmade gambling tokens as well as tobacco pipes and skillfully made metal products.
Dr Tuffin said the coins were found in the clay floor of the workshop where copper casting would have taken place.
Convicts were punished for being in possession of money, and it is presumed a crafty inmate stole the coins from an officer and hid them away.
"Someone with access to the workshop has been able to make their way to a relatively hidden part of the workshop and has put it in the clay and haven't been able to come back and reclaim it," he said.
"It could have been because they were suspected and their access to the workshop was denied, or because they were sent to Hobart to be released."
A coin expert, known as a numismatist, will be engaged to analyse the shillings, which date between 1814 and 1844.
Dr Tuffin said it was likely the coins were stolen in the 1850s.
Who had access to the workshops?
About 10 per cent of the convict population, which at its peak was 1,200 men, were working in the workshops at any one time.
Given they had access to sharp tools and fire, it would not have been a job for the colony's most hardened criminals.
"You find the better behaved population are working in the workshop and they are men who have skills," Dr Tuffin said.
"You generally want men you can trust working in these spaces."
Many of the convicts were skilled tradesmen before being transported, which is shown in the work, he said.
"The work that's happening in this place is incredibly skilled, in the 1840s they are casting Port Arthur's peal of bells which is an incredibly complex process to be doing," he said.
The dig found hundreds of kilos of metal-working waste and could even pinpoint where the men would have been standing.
"We also found the anvil itself which was a pretty interesting turn up," he said.
"You get a nice link to the past when you find objects like that."
Black market at Port Arthur
Just like at a modern prison, there was a black market operating within Port Arthur.
"Back then it was tobacco and gaming," Dr Tuffin said.
"We know they made their own currency."
He said possession of the banned items like handcrafted gambling tokens uncovered at a previous dig at the penitentiary would have created a hierarchy among the convicts.
Dr Tuffin said it had been assumed that convicts would not have been permitted to smoke tobacco while working.
But tobacco pipe remnants were found throughout the workshop.
"The fact that we are finding fragments indicates to us they are still being permitted to be smoking while at work," he said.
He said the pipe discoveries helped to conjure up the daily experience of convicts working away as blacksmiths while smoking tobacco.
The dig was the third and final stage in a series of excavations spanning almost a decade and part of a broader investigation into hard labour at the site and how it evolved over the prison's 47 years of operation.
A tricky dig
The site of the excavation was chosen to help fill in the convict story and learn more about the hard labour convicts were forced into.
The workshops were occupied from the 1830s when transportation began, and were used until 1877.
They went through several phases, including being used to make shoes, as well as for copper and iron works.
To tourists visiting the Port Arthur site, it appears to be just grass among other ruins — but what lies beneath tells an important story in Australia's convict history.
"It was a hub of activity, it gives us an opportunity to share that with our visitors," Ms Szydzik said.
She said the excavation was a particularly tricky dig because the site had been damaged by bushfires in the 1890s.
"It was very technically challenging," she said.
The findings will now form part of the site's interpretation for tourists.
Ms Szydzik said experts were still discovering new things about Port Arthur all the time.
"Everyone's always finding out more about the history of the place and what happened here," she said.
