The Retronaut.

Nietzsche owned one of these. Here’s a poem he wrote about it.

‘The Writing Ball is a thing like me: of iron
Yet twisted easily – especially on journeys.
Patience and tact must be had in abundance
As well as fine [little] fingers to use us.’

(Not quite as memorable as – ‘That which does not kill us makes us stronger’, but we all have off days) ; )