Now invisibility is a violation of fairy traditions, while ghosts are very often invisible—these rapping and stone-throwing ghosts, always. It might be urged that this spirit was a Bwbach, if a fairy at all, seeing that it kept pretty closely to the house; but on the whole I choose to class it among the inhabitants of the spirit-world; and really, the student of folk-lore must classify his materials distinctly in some understandable fashion, or go daft.
