A large proportion of these stories of ghostly perturbation concerning hidden treasure include a further feature of great interest, relating to transportation through the air. I have mentioned that ghosts sometimes employ the services of the fairy Boobach in thus carrying mortals from place to place. The fairies of Wales are indeed frequently found to be on the best of terms with the ghosts. Their races have much in common, and so many of their practices are alike that one is not always absolutely sure whether he is dealing with a fairy or a spectre, until some test-point crops up. However, in transporting a mortal through the air, ghost and fairy work together. The Boobach being set his task, complaisantly gives the mortal the choice of being transported above wind, amid wind, or below wind. The value of knowing beforehand what to expect, was never better illustrated than in this place. The mortal who, with a natural reluctance to get into an unpleasantly swift current, avoids travelling mid-wind, misses a pleasant journey, for mid-wind is the only agreeable mode of being borne by a Boobach. Should you choose to go above wind, you are transported so high that you skim the clouds and are in danger of being frightened to death. But choosing the below-wind course is even worse, for then you are dragged through bush, through briar, in a way to impress upon you the advice of Apollo to Phaeton, and teach you the value of the golden mean. _In medio tutissimus ibis._