In the early fifties we used to play two balls against a wall to:-

One, two, three alairy
My ball's down the airy
Don't forget to give it to Mary
And not to Charlie Chaplin.

The we knew the airy as the area down the steps outside the basements that housed the kitchens in Victorian houses.
I noticed recently in "Upstairs Downstairs" that several times they referred to this space as the area.
We always thought that Mary was a reference to Mary Pickford who started United Artists with Charlie Chaplin.