Tim tests his lungs... with surprising results

(CBS News) What is it with British accents? Everything our friends across the pond say sounds more intelligent, refined and charming. Even when the subject of their discussion is a strange, Welsh breathing invention... thing. We're not quite sure what it does -- and neither is Tim. But he gamely decides to "have a go" and discovers the device's secret. What secret is that? You'll have to click play to find out.

Spoiler alert: it's a prank! A quaint, British prank. Maybe not the most original prank in the world, but we sure didn't see it coming. But as good as the trick is, it's still not as amusing as Tim's perfectly British reaction. He's about one "I say!" short of a stereotype.

"Quite clever" indeed.