Miles Kington: Welcome to the house of forgotten fun

' "What do you call a man who steals pigs?" "A ham burglar!" We don't laugh, again'

"KNOCK KNOCK," says Basil Friday.

"Who's there?" I say.

"Wurlitzer," says Basil Friday.

"Wurlitzer who?" I say.

Basil Friday suddenly bursts into a crude parody of Elvis.

"Wurlitzer one for the money, two for the show, three to get ready and go, cat, go!"

He does it quite well, and it's quite funny. But neither of us laughs. We're not here to laugh, after all. This is the new Heritage Joke Museum, where they take jokes extremely seriously. Or, at least, the museum's director, Basil Friday, does.

"Knock knock jokes have proved surprisingly long-lived," continues Basil. "Children still like them, even though it's very rare to find a new one these days. But lots of other joke formats have vanished. Utterly disappeared. There are kinds of jokes that people were still telling up to 10 years ago that never get told any more. And they would have disappeared entirely if it were not for our work here at the Heritage Joke Museum, where we specialise in preserving old joke forms..."

Do jokes actually end up vanishing so completely?

"Oh, Lord, yes. Whole families of jokes vanish when they're worn out. Remember the elephant jokes?"

I don't think...

"How do you get four elephants inside a mini?"

I don't know.

"Two in the front, two in the back."

We don't laugh, again.

"Lots of elephant jokes like that a while back," says Basil, "and you never hear one these days. Actually, I sort of like the elephant jokes, because they have a surrealist edge to them and don't just depend on puns, as most of today's kids' jokes do. What do you call a man who steals pigs? A ham burglar!"

We don't laugh, again.

"It's interesting how many joke formats take the form of riddles," says Basil. "A modern sophisticated form of the riddle joke is the lightbulb riddle – how many feminists does it take to change a lightbulb? and all that – but there have been lots of other riddle formats. What do you get if you cross a something with a something, remember those? What do you get if you cross a kangaroo with a sheep? A woolly jumper. And there was a format back in the Fifties which was quite popular for a while and went along the lines of: 'Why did the cowslip? Because she saw the bulrush'..."

Again we don't laugh.

"But that all goes at least back to Victorian times, when riddles involved really gruesome punning answers. Like: 'Why is an onlooker like a bad potato? 'I don't know. Why is an onlooker like a bad potato? 'Because they are both spectators (specked 'taters)!' "

He doesn't laugh. Nor do I. Not at all.

"Another one? 'Why is a railway engine like a naughty schoolboy? Because they both have a tender behind!' Now, that is interesting, because not only is it unfunny, it is incomprehensible to anyone under 50. With the end of corporal punishment, schoolchildren no longer get caned, and with the end of steam trains, engines no longer pull a tender behind them. You see, when technology changes, it makes a whole lot of jokes obsolete. Like the one about the man who got in the train and thought the compartment was too hot... Know that one?"

Don't think so...

"So he turned the heating down. Another man got in, felt cold, turned the heating up and opened his book. When he was busy reading, the first man carefully reached out and turned the heating down, then opened a paper. Using the cover of the paper, the second man reached out and turned the heating down again, and this went on for a while until the door of the compartment burst open, and there stood the engine driver with a lump of coal in his hand, shouting: 'Well, d'you want the bloody thing or don't you!' "

We both laugh.

"Now, I have tried that joke on young people and it always falls flat because they don't know about compartments in trains, they don't know what coal would be doing on a train, and they have never come across individual heat controls. But you and I laughed, partly because it's quite funny and partly because we had special knowledge and felt pleased with ourselves."

More about this amazing place some other time...