This packed metal tube became our home in the sky.

For the machine to work its magic, you have to lie down inside a big metal tube for between 30 minutes and an hour.

Especially when you're hurtling through the troposphere at 500mph in a fragile metal tube with 300 strangers.

He slid the metal tube into the inside pocket of his anorak, then set off eastwards along the riverside path.

Indeed, for most of my early life my tongue was more adept at articulating semiquavers through a metal tube than at turning thought into speech.