THE two final pieces of a giant puzzle – each weighing 1.25tonnes – were delivered to Houghton Mill on Monday (November 12).

National Trust volunteers watched as the French burr millstones were lifted to the first floor of the 18th century mill, and then rolled into position in a far corner.

The recycled millstones, originally from the Marne Valley in France, were repaired at Dorothea Restoration's base in Bristol before being transported up to Houghton on Monday morning, marking the finale of a project 18 months in the making.

Phil O'Donoghue, operations manager at the National Trust-owned mill, said: "It's a really exciting time for the mill. We are now going to be able to demonstrate the mill to visitors at the touch of a button because the new stones will be powered electronically.

"The millstones were delivered through a door on the first floor and then rolled to the other side of the mill - just like it would have been years ago. The stones are made from French burr and are stronger than English millstones, and last longer.

"When the new stones are ready to use, we will be able to show visitors how the mill works at all times. There have been times when the river levels have been too high and we have had to say there is too much water for the wheel to go round, which some people don't understand."

Houghton Mill already produces some flour, but the new millstones could see the amounts significantly increase - about 36,000 1kg bags of flour next year.

Mr O'Donoghue said that they hoped to produce and provide more flour, made from grain grown at Wimpole Hall Farm, to local outlets to sell - a move that would also improve awareness of the mill.

Sandy Curr, who led the £36,000 project, said: "This has been 18 months in the making, but the idea goes back longer so we're relieved that will be over soon. It is a fantastic time for the mill, and we have been able to keep the costs down because the project has been volunteer-led."

Geoff Wallis, of Dorothea Restoration, worked with his son, John, who now runs the family restoration business, to roll the stones across a narrow track through the mill.

Mr Wallis said: "The French burr, which is cut from freshwater quartz quarries next to the Seine close to Paris, comes in blocks and has to be banded together with metal and we were able to use the original banding for the base stone. Not only is the burr stronger, it has sharp edges which provide a good quality flour."

The new millstones will be ready for when the mill reopens in March.

INFORMATION: For more details on the project, or if you are interested in becoming a volunteer, call 01480 301494.