It has been played on by generations of children – but until now this steam powered road roller has been something of a mystery for most of those who climbed on it, or parents and grandparents who watched their offspring have fun.

But all has now become clear with the unveiling of an information board at the King's Road playing field in Dorchester.

And this Sunday, December 16, a working version of the Eddison roller will be trundling into town to take part in a gathering of vintage vehicles at the Top o' Town car park.

Helping Dorchester mayor David Taylor unveil the new board, provided by the town council, on Monday, was Nick Aplin, vice chairman of the Transport of Yesteryear Group which organises the Christmas Steam and Vehicle Meet – previously held at the Sun Inn.

Nick's dad, Will Aplin, worked on the engine which has been at the playing fields since the early 1960s and helped with its move there.

The plaque tells the story of how the company started life in Martinstown, eventually moving to Dorchester, manufacturing steam engines which were used throughout the country and abroad.

Frank Eddison started the business in Leeds, moving south in 1870 and starting, in 1877, the Dorchester Steam Plough Works on the Wareham Road.

When farm use declined the company moved into hiring out steam rollers for road building and became the Eddison Steam Rolling Company with the slogan “Eddison Everywhere”.

Worn out engines were donated by the company to children's playgrounds – including the one gifted to Dorchester in the early 1960s, a ten ton road roller originally built in 1922.

By 1904 Eddison's had 150 traction engines and steam rollers at its Dorchester base – with the men starting early in the day – leading Thomas Hardy to write and complain about his sleep being disturbed at 5.45am by the sound of a siren to summon people to work.

The Wareham Road works shut in 1965 with the company, by then owned by BET, moving to the Grove Trading Estate. The company closed in the 1970s.