Weekendish: Petrol, crime and Frank Sidebottom

A round-up of some of the best long and short reads, as well as video, from the BBC News website this week, with your extra comments.

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When Thomas Midgley created tetraethyl lead - a compound that would make car engines more efficient than ever - he couldn't have foreseen that more than 90 years on his creation would be at the centre of a debate over crime. Lead theorists reckon that the stuff we added to our petrol caused a decades-long crime wave that only started abating as lead was removed from our environment. They say that data they've collated and calculated from each nation shows the same 20-year trend - the sooner lead is removed from the environment, the sooner crime will begin to fall. But not everyone agrees. Some criminologists argue that this theory is just the latest in a long history of people trying to link biology to crime. The other theories, they argue, keep being disproved. Nick Gargan, Chief Constable of Avon and Somerset Constabulary, tweets: "Here's a theory I don't remember seeing before. Economist reporter Daniel Knowles tweets: "The problem with the lead hypothesis - which may not be fatal - is the lack of backing longitudinal data," while Dr Greg Wilson ‏adds on Twitter: "Fascinating but can't see how we could prove it." Kate Griffiths-Lambe tweets‏: "Appreciation of neuroscience & biological response is slowly growing, could leaded petrol be a prime cause of crime?"

Did removing lead from petrol spark a decline in crime?

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The Harlem Hellfighters. This was the name given by the Germans to US 369th Infantry Regiment, an all-black military unit that proved crucial in the trench warfare during World War One. They had trained in South Carolina, where they were taunted and subjected to beating. But they were ordered not to fight back - so they didn't. Max Brooks has told their tale in a new graphic novel. In our Picture This video, he describes their discipline and self restraint as nothing short of heroic. In 1919, the unit returned to New York as decorated heroes, but were plunged into some of the worst racial violence the country had ever seen. "Wow just wow, #HarlemHellfighters, an African American regiment in #WW1," tweets Rowun Giles.

Harlem Hellfighters: The all-black regiment of WW1

It's fair to say that we mostly associate France with coffee. As a result, for generations, the search for an acceptable cuppa has been an obsession of expatriated Brits. But this week, Hugh Schofield reported that specialist tea salons are spreading, in Paris and beyond. People take classes to learn how to taste and to serve. Literally hundreds of varieties and blends are now available for sale. But what the French are developing is something altogether more refined and delicate - as befits their gastronomic heritage. You won't find any builder's brew here. Apparently, at the tea auctions in China, you can spot the British. Didier Jumeau-Lafond of Dammann Teas, based in Dreux, say the Brits want the cheapest prices, while the French want the best quality. "Ours is a niche market, but it's a niche that is growing fast," he says. Geraldine Rowe ‏tweets: "So now the French are even looking down their noses at us for our taste in tea, while David Andress adds on Twitter: "Ah, the French, still making a nice cuppa into something poncy, after all these years..."

France's silent tea revolution

There are those that say the people at the British Standards Institution have the best job - they get to smash windows for a living. They get to do things like swing a big pendulum into a glass door to ensure the glass breaks safely. The BSI has been setting safety standards for products - anything from glass and fire extinguishers to condoms - for more than 100 years. Now its specialised test facility has had a multimillion pound makeover. Watch how, among other thing, experts ensure a door really is burglar-proof.

Standards testing lab gets multimillion pound makeover

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Image caption Frank Sidebottom's Fantastic Shed Show ran on ITV in 1992

The giant home-made head. The ridiculously nasal Mancunian voice. The anarchic and absurd humour. The deliberately naff pop songs. That was Frank Sidebottom. Frank was the comic persona created by Chris Sievey, from Timperley, Greater Manchester, who died in 2010. Now a film about the bloke with the papier mache head is about to hit the big screen, starring Michael Fassbender. This Frank, however, is from Bluff, Kansas. Sievey didn't want the film to stick to the facts because he didn't want the "reality of Chris to undermine the mystery of Frank". So who was the real Sievey? His real story is arguably more interesting than the one portrayed in the film. Oli Putland ‏tweets: "The more I read about Frank Sidebottom, the more bizarre it seems that I worked with him at all." Stephen Jackson ‏tweets: "Nice BBC piece for those loons who have no idea about the magnificent @mr_sidebottom."

The real story of Frank Sidebottom

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For centuries, gardeners have put shards of pottery - "crocks" - at the bottom of plant pots to increase drainage by creating big gaps. But a new study has debunked the tradition. Apparently it can worsen drainage by creating blocks. Like many gardening "tips" it probably owes more to Victorian fashion than practicality, writes Tom de Castella. John Bourn writes on Facebook: "I've been using dead leaves to sub for crocks for the past forty years and find everything to be fine. Pots drain naturally and the root system holds onto the leaves if you leave a little to long." Eleanor Relf adds, "I put crocks - but not for drainage. The crocks simply stop the soil falling out through the holes! If I want to increase the drainage I mix grit sand into the soil and heap a bit over the crocks too....and in this case the crocks function perfectly, stopping the sand falling out through the holes." Ed Kervan adds: "This is not new information. I learned this years ago in horticulture school. Soil drainage is all about aggregates."

Are gardeners wrong to put 'crocks' in plant pots?

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