Ken Dodd explored what makes people laugh

Event organisers have said the week-long festival has been a success and they are confident visitor numbers have exceeded the 15,000 expected.

Other guests at the event, billed as the largest of its kind in England and Wales, have included Ken Dodd, Bill Oddie and David Bellamy.

The festival, which opened on Monday, has hosted 200 events covering topics ranging from the creation of virtual limbs to a cure for cancer.

Valerie Cordell, a member of the festival taskforce, said: "The organisers are confident the audience numbers are up on last year.

"It has exceeded all expectations, there have been more events this year and many events have been a sell-out.

David Bellamy talked about healing the world

"It has covered a wide range of topics from serious subjects to silly ones."

On Saturday, Geller asked people at his show at the William Aston Hall in the town, to take along broken clocks and watches so he could demonstrate his mind-bending powers.

He has also been testing his powers of extra sensory perception (ESP) over the internet on the North East Wales Where I Live website.

Geller urged internet users to concentrate their minds on fixing watches or bending spoons.

The results of the experiment will be revealed on Monday.

Geller became well known to television audiences in the 1970s for his claims to read minds, mend viewers' broken watches through mind-power alone and for bending spoons using the same technique.

Humour study

On Friday comedian Ken Dodd explored the psychology of humour and took part in a scientific study into what makes people laugh.

Meanwhile, the botanist and broadcaster professor David Bellamy gave a talk on ecology and the healing of the world.

Earlier in the week birdwatcher and television presenter Bill Oddie entertained audiences with a talk on his lifelong passion for birds - and his desire to find the Birds of Paradise in New Guinea.

The festival was set up in 1998 and has been organised by Wrexham County Borough Council, Yale college, North East Wales Institute (Newi), the Welsh Development Agency, and Education and Learning Wales.