Trust restores 'personal aesthetic' to Petworth: A Turner sketch is being used to rehang pictures at a historic country house, writes Oliver Gillie

The Joshua Reynolds painting Macbeth and the witches is back in the Square Dining Room at Petworth House, West Sussex, as it was when J M W Turner sketched the room in 1827. The room, along with most of the house, is being restored to look as it did when the 3rd Earl of Egremont presided and spent many hours consulting with Turner and other artists who made it their home.

Sir Anthony Blunt, former Keeper of the Queen's Pictures, rehung the pictures at Petworth in 1952, when the house was acquired by the National Trust and made into a museum. The Square Dining Room ceased to be a place where a visitor might imagine having a grand meal and became the Van Dyck room. In other parts of the house Blunt ordered paintings school by school as if it were an academy.

Turner's sketch shows that the paintings were originally hung symmetrically to produce a decorative effect. Reynolds's Macbeth painting is an indifferent work which has deteriorated badly. Even so, placed in the centre of the wall as it was when sketched by Turner, it develops a grandeur which is set off by the small gems around it.

Christopher Rowell, historic buildings adviser to the National Trust, looked critically at his hang and lowered one picture by an inch or two and lifted another by a fraction. Putting himself into the mind of the 3rd Earl he attempted to obtain the perfect degree of separation between pictures.

'Turner may have devised this arrangement himself and drawn the sketch to show the Earl what it would look like,' Mr Rowell said. 'Whatever the reason, it is a rare thing to be able to recreate a room according to a scheme that he obviously approved of.'

Apart from the witches, the only other painting that can be clearly identified from Turner's sketch is a portrait of the 10th Earl of Northumberland and his family - a strong but delicate painting by Van Dyck.

It is not possible to be certain of the identity of the smaller paintings sketched by Turner, except for one in an oval frame that hangs above the witches, probably a self- portrait by Reynolds. Mr Rowell overcomes this problem by making use of lists of paintings made 20 years later which quite probably include many of the paintings sketched by Turner.

The National Trust is taking a bold decision in returning to an early 19th-century scheme with walls densely covered in up to four tiers of pictures - Sir Anthony Blunt's hang generally occupied only two tiers.

Blunt saw himself as putting order into a rather meaningless accumulation created by the the 3rd Earl and his descendants. Now the National Trust has found virtue in the mess.

'The pictures were constantly being rearranged in the 3rd Earl's time,' Mr Rowell said. 'Visiting artists were free to take them down for copying and they were not always put back in the same place. Blunt's approach was logical and historic but it overlooked the personal aesthetic.'

(Photographs omitted)