This great force of gravity is not _always_ in the saddle.

Sometimes it just is not there--and I lean strangely against a wall.

I have been even known to turn upside down, with my wheels in the air; spun by the same mysterious Miss.

So that I must introduce a theory of Relativity.

However, mostly, when I am awake and alive, she is in the saddle; or _it_ is in the saddle, the mysterious force.