SOMETHING of a mystery will emerge at a sale in Dorset on February 14. The 15ins-high slipware vase (pictured) is a typical example of the desirable ceramics produced in North Devon since the Medieval period. But what makes this pot even more special is the decoration – it is upside down!

Amy Brenan, a valuer at Duke's Auctioneers, Dorchester, said: 'At first glance, the incongruity is not really visible. The ornate scrolls keep the eye busy but it is only on closer inspection that the bird and lion motifs are all upside down.'

In recent years, Devon slipware has become highly desirable. Widely produced in towns such as Bideford, Devonshire potters in the 18th and 19th centuries were inspired by the farming and seafaring traditions around them so their wares were more often than not decorated with wheat sheaves, animals and boats, not the exotic lions and birds with which this example is decorated.

'Many of the ships departing Bideford were destined for the Americas and this style of pottery soon became popular over there. It could be possible that this particular pot was commissioned for someone abroad who may have been wealthier and with more grandiose tastes, than those that the pottery was originally intended for at home in Devon. This might explain the more refined decoration.

'However, the reason for the upside down decoration is a mystery: Comparable punch bowls featured in the "Longridge Collection of Slipware", the key reference about slipware, have similar "upside-down" decoration and it has been suggested that this is because the vessels were stored upside down,' said Amy Brenan.

Whatever the reason, the vase is an excellent example of its type and it is thought likely to achieve its £2,000 to £3,000 estimate when it is offered for sale at Duke's Auctioneers in?Dorchester on February 14.