'Peasant Da Vincis' on show in Shanghai exhibit

The movable metal fins on Li Yuming's homemade submarine are designed to make it swim like a fish, but with no engine it cannot go forward or even return to the surface once launched.

"Minor problems," says the Chinese peasant inventor, who insists funding is all he needs to make it functional.

Like a giant rusty goldfish, Li's two-metre-long metal submarine hangs in the air at Shanghai's Rockbund Art Gallery, surrounded by planes, helicopters, flying saucers and other Peasant da Vincis.

The collection is a new exhibition by Chinese artist Cai Guo-Qiang, whose gunpowder on canvas designs won the Hiroshima Art Prize for peace and whose fireworks for the opening of the Beijing Olympics dazzled the world.

Mr Cai was fascinated by the humble handcrafted charm of the whimsical inventions by Chinese peasants - robots, flying machines and even an aircraft carrier - which he said were "borne out of a desire to escape the gravity of one's circumstances".

"I was very touched by their uselessness, like the submarines. Once they sink they can never float back up," Mr Cai said. "It's the same with artworks, they're pretty useless, but everyone takes them very seriously."

The idea of combining the inventions with his own art in halls featuring grass and chirping birds sprang from an exhibition he curated for the 2005 Venice Biennale that included peasant Du Wenda, 44.

Obsessed by flying saucers since seeing a copy of Science Fiction magazine at the age of 10, Mr Du had hoped to fly one of his homemade craft at the show.

But Mr Cai said it soon became clear that if it did fly, he would be unable to land and the homemade craft would fall apart. He consoled Mr Du, who feared he had shamed his nation.

"It's not a big deal," Mr Cai recalled telling him. "The world has the highest respect for Italian inventor Leonardo da Vinci, but none of his inventions were ever completed."

Now Mr Cai and his peasant collaborators are providing a counterpoint to the slick presentations nearby at the six-month, multi-billion-dollar Shanghai World Expo.

Peasant inventor Wu Yulu, 48, took over a gallery floor, turning it into a robot workshop where two creations paint dots and splashes in the style of Damien Hirst and Jackson Pollock.

Other robots jump, dance and pull a rickshaw.

The stories of the inventors such as Mr Wu - who hopes his robot offspring such as Big Wu, Second Wu, and Third Wu will lead to fame and fortune - are as captivating as the creations.

Sixty-eight-year-old farmer Wu Shuzai's wife tore apart his first wooden aircraft for firewood to teach him not to waste limited resources.

His chicken coop-like aircraft may have never taken wing, but he still dreams of flying over his mountain village and seeing the world in it.

Wang Qiang, a 34-year-old hairdresser, has actually flown in his planes powered by a second-hand 250cc motorcycle engine and fashioned out of hand-carved propellers, metal tubes and plastic bathroom pipes, covering distances of up to three kilometres at speeds of up to 120 kilometres per hour.

"In the city we are obsessed with always going faster but the peasants from the countryside are working hard to chase after their dreams and it's something that we should learn from," Mr Cai said.

But in a reminder of the dangers faced by these self-taught Da Vincis, the exhibit includes the shattered motor of the wrecked plane 50-year-old Tan Chengnian built as a gift for his wife. He died in a trial flight in 2007.