The political effect of such vehicles maybe enormous, as they can go over land and sea, and can cross most reasonable obstacles as if they aren't there. You could have the great ports of the world at the centre of the continents, if you wanted to.

That private hovercraft will ever be popular, I rather doubt. They are noisy and have poor efficiency and poor control. You can't put on the brakes in a hurry if you're riding on a bubble of air.

However, they are splendid for opening up terrain where conventional vehicles cannot travel, such as shallow rivers, swamps, ice fields, coral reefs at low tide, and similar types of fascinating and now inaccessible wilderness.

I hope to see the automatic car before I die. Personally, I refuse to drive a car, I won't have anything to do with any kind of transport in which I can't read. I can see a time when it's illegal for a human being to drive a car on a main highway.

More seriously, we'll certainly have to get rid of the petrol engine, and everybody is now waking up to the urgent necessity of this.

Apart from the facts of air pollution, we have much more important uses for petroleum than burning it. To make non-petrol cars and other vehicles practical, we need some new power source.

Fuel cells are already here, but they are only a marginal improvement. I don't know how we're going to do it, but we want something at least 100 times lighter and more compact than present batteries.