IN THE heart of the Dorset countryside, a small factory is making ox carts for Africa. It usually makes acoustic ventilation systems - it has just finished the one for Canary Wharf - so why carts for Africa? Richard Nethersole, who owns the factory, shrugs. 'I met him, didn't I?' he says, gesturing towards a florid- faced, white-haired old gentleman with half-moon glasses who could pass as a mad professor.

He is Harold Poole, the man who designed the 'Zebra' cart more than 40 years ago and recently discovered that Africa's need for it is greater than ever. He has charged into the project of making the carts again with all the enthusiasm of a young inventor ('I'm 72 in August, and it's time I stopped frigging about' - peal of plummy laughter).

Mr Poole is also the designer of the Poole Tractor Coupling - 'It's called a weight transfer hitch, but that's all frightfully boring' - the patent for which sold all over the world and gave him a very comfortable living. But the invention he loves is the ox-drawn cart.

Having served on Field Marshal Montgomery's staff in the Second World War and trained as an engineer, Mr Poole went to Africa in 1949, liked it, cabled for his wife and three children to join him and set up a workshop in Salisbury, now Harare. He built a business making farm trailers and then designed the ox cart which, in theory, solved the problem of getting African produce to market.

But how could African peasant farmers afford it? 'The basic problem was not making the cart, but getting it to the native farmer,' says Mr Poole. 'They had no money. I tried to persuade the government of Northern Rhodesia to buy them and give them to the Africans. They said, no way - politically impossible. So I set up the African Farmers' Improvement Fund, a credit system by which they were given a cart and paid back with maize.'

Mr Poole pulls out a 1956 Northern Rhodesia Department of Agriculture report showing a leap in maize sales by African farmers from 61,000 bags in 1949 to 595,000 bags in 1954. 'That's what transport did,' he says.

'I saw great prosperity happen. I saw people who had been poor suddenly not poor any longer - that's what private enterprise is all about. I like Africa and the African and I think he's had a rough deal and that inspired me - enabling people to make their own money, that's what is so exciting.'

By the end of 10 years his factory employed 200 Africans and was turning out 400 carts a month. He made 25,000 of them.

In 1985 he was back in Zimbabwe on business when he met James Chikerema, a representative of Lonrho. 'Are you the Harold Poole who used to make the farm carts?' asked Mr Chikerema. 'I was running a school then. I bought eight of them in 1953 and they are still working. Come back and do it again.'

Mr Poole didn't go back, but he persuaded Mr Nethersole's company in Dorset to make the steel frame in kit form and export it. 'It's exactly the same as I made in Rhodesia, rolled steel wheels, steel frame and indigenous hard wood - you can't use our soft woods because the white ants would eat it,' he says.

The problems are exactly the same as those of 40 years ago.

A recent World Bank report on rural transport in Africa says:

'Inadequate road transport and lack of off-road transport . . . seriously constrain the growth of rural economies . . . traffic on most rural roads consists mainly of pedestrians, often carrying headloads.'

But why make something so simple in Britain and not in Africa? 'It has to be at the moment. There's no point in sending out the steel, or anything that can be made into anything else, because it will be stolen and the carts will not reach people who need them,' says Mr Poole. 'But it would be a tragedy if we were still sending out the kits in 10 years' time. There's no reason why it should not be made there.'

The main problem is finance. Few African farmers can afford the pounds 338 for a cart, so someone - the government or aid agencies - has to sponsor the project. 'Everyone says that's what we need but we can't get it,' says Mr Poole.

The Ugandan government was interested, but all the draught oxen were eaten by the previous government's army, so they asked him to look into a bicycle-drawn cart instead. He's already designed one.

(Photographs omitted)