I sat with my eyes riveted on the compass, following with some difficulty its rapid changes.

The needle swung to and fro incessantly but always within a definite arc, the centre of which was the true direction.

But this direction varied from minute to minute in the most astonishing manner.

West, south, east, north, the carriage turned, "boxing" the compass until I lost all count of direction.

It was an amazing performance.