There's no earthly way of knowing
Which direction they are going!
There's no knowing where they're rowing,
Or which way they river's flowing!
Not a speck of light is showing,
So the danger must be growing,
For the rowers keep on rowing,
And they're certainly not showing
Any signs that they are slowing...

Roald Dahl

http://www.poemhunter.com/poem/there-s-no-earthly-way-of-knowing/