Climb out of that trench

'You guys in the trench,' shouted the foreman. 'Can you climb out a minute.'

And out they clambered.

'Stamp your feet as hard as you can,' he ordered. And they did.

'Now jump back into the trench, then jump out and stamp your feet again.'

'Excuse me, sor,' muttered O'Rafferty, 'would this be some kind of pagan ritual or such like?'

'No,' said the gaffer, 'you're bringing out more soil with your boots than you are with your shovels!'