long-legged fly

...
That the topless towers be burnt
And men recall that face,
Move most gently if move you must
In this lonely place.
She thinks, part woman, three parts a child,
That nobody looks; her feet
Practise a tinker shuffle
Picked up on a street.
Like a long-legged fly upon the stream
Her mind moves upon silence.
...
- William Butler Yeats