‘People don’t realise if we stop producing engineers, then we really have a problem’

“Have you heard the one about alum?,” he says, embarking on one of his favourite tales from the world of science. “Well, back in the 16th-century when Henry VIII had his great row with the Pope, it had unexpected ramifications. In those days clothes were made from wool and a chemical called alum was vital in the dying process.

“Unfortunately, all the world’s alum came from the hills just outside Rome and with Henry doing his own thing, the Pope immediately stopped all the supplies to England. Scientists began looking for alum in various parts of this country, but drew a complete blank. However, the really interesting thing is what happened next.

“Some incredibly clever people discovered that if you took shale from the cliffs around Ravenscar in North Yorkshire, roasted it for nine months over large bonfires and then mixed it with stale human urine, hey presto you get alum.

“The alum industry provided work for hundreds of people over a quarter of century. No one knows who first discovered this peculiar method of production, but there are examples like that right throughout history. For me it’s stories like this that show the real beauty of science.”

Smithson Tennant is another of Hart-Davis’ heroes. The 250th anniversary of the Selby chemist, who in the 18th century discovered two elements in the periodic table, is being celebrated this week at York University where Hart-Davis himself studied chemistry.

“Great scientific discoveries often have very ordinary beginnings,” he says. “It’s the same with Smithson Tennant, who really was one of science’s good eggs. At the time the process for extracting platinum from crude ore left behind a gritty black powder. Most assumed it contained nothing of value and he was the only one to realise the value of the residue. He discovered it contained two new elements.

“The first he called iradium because it irradiated a lovely spectrum of colours and the second, which had a rather pungent odour, he called osmium after the Greek word for smell. He’s not a name that perhaps many know, but if it wasn’t for people like him then the world of science would be a much poorer place.”

Hart-Davis is never happier than when waxing lyrical about the achievements of fellow scientists. It’s his passion and slight eccentricity which first made him a hit both on Tomorrow’s World and the Local Heroes series which saw him travel the country on a bike in praise of forgotten scientists.

A number of other television projects followed, but over the last few years he admits that broadcasters have been reluctant to embrace science as a format. They think, he says, it’s too dull to attract decent ratings.

“Ok, so there’s Brian Cox, but name another scientist who is regularly on television? You can’t, because there isn’t. It’s almost impossible to get anything made and I honestly believe that’s because the media is run by people who almost exclusively have a background in the arts. That’s the reason why Melvyn Bragg is always on the box.

“A little while ago, I did a series for Radio 4 on great engineers. There was only five episodes, but the audience figures were great and it was voted the best new series of that year. So, we went back the following year and said how about another series and you know what they said? They said, ‘Oh, no sorry we’ve done engineering now’.

“They wouldn’t say, ‘sorry, we’ve done music after a series on Mozart, would they?

“I still get emails from people about Local Heroes. It’s 10 years since that series went out, but it shows there’s still an appetite for science on television which isn’t being satisfied.”

While Hart-Davis still makes the occasional guest appearances on television much of his time recently has been devoted to writing. The Book of Time – Everything You Need to Know About the Biggest Idea in the Universe came out last month.

A doorstep of a book, he admits there were times when he thought he would never get it finished and by way of light relief he has also been working on a pop-up book of scientific inventions for children.

“You pull a piece of card and it makes a steam engine work and the whole thing has been an awful lot of fun,” he says. “The only tricky part was picking which inventions to illustrate. At first I had a list which included dishwasher, washing machine, iron. However, the publisher did say that as we were specifically targeting boys, it might not be a good idea to be too domestic.”

The book is part of Hart-Davis’s attempts to switch children onto science. Changes in the syllabus which have seen hands-on experiments replaced by lessons of theory along with the merging of individual subjects into one bland general science course have been blamed for a decrease in those taking chemistry, physics and biology to A-level and beyond.

Successive governments have pledged to address the problem, but science is still a subject which turns many youngsters off.

“There has been a slight increase in the numbers taking physics degrees, which has to be a good thing as physics is the most important of all the sciences, but there is still a problem.

“What people don’t realise is that if we stop producing engineers then we really will have a problem and if we don’t catch children when they are young, it becomes almost impossible to fire their imaginations when they are older. I had a maths teacher called Jack Turner. He was Canadian and as I remember rather pedantic, but just as I was about to leave school he collared me in the corridor and said, ‘Hart Davis, I’ve one thing to say to you’, and I said ‘Yes, Sir’, and he said ‘Science’. I had no idea what he was talking about really, but the fact is that I remember it now. I think he started me off on an enquiring streak, and I’ve been doing science ever since.”

Archimedes is Hart-Davis’ all-time scientific pin-up, along with the likes of James Watt, but if he could invite anyone to dinner it would be Erasmus Darwin, grandfather of Charles.

“He was a physician, an inventor, a poet, a natural philosopher and as it turns out something of a sexpot. He had four sons and one daughter with his first wife, then when she died he had an affair with the governess employed to look after his children.

A few years later, he married again and fathered another seven children, which was all quite impressive for a man who was fat, ugly and pockmarked. However, he was also incredibly well respected. He operated out of Lichfield and the story goes that one day a man travelled all the way from London just for a consultation.

“Having successfully diagnosed his complaint, Erasmus apparently turned to him and said. ‘You’re very welcome to come to Lichfield, but why can I ask did you not go to see the eminent Mr Warren in London? ‘Because,’ said the man, ‘I am Mr Warren’.”

And there he goes again, another story about another science great.

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