was once waged on account of a Bull, by the hosts of Queen Meave against those of Cuchulainn the hero of Ulster. Let him be lost in the mists on the top of Ben Bulbin. Let him know the haunts of fairy kings and queens in Roscommon. Let him follow in the footsteps of Patrick and Bridgit and Columba. When there are dark days and stormy nights, let him sit beside a blazing fire of fragrant peat in a peasant's straw-thatched cottage listening to tales of Ireland's golden age--tales of gods, of heroes, of ghosts, and of fairy-folk. If he will do these things, he will know Ireland, and why its people believe in fairies. As yet, little has been said concerning the effects of clouds, of natural scenery, of weird and sudden transformations in earth and sky and air, which play their part in shaping the complete Fairy-Faith of the Irish; but what we are about to say concerning Scotland will suggest the same things for Ireland, because the nature of the landscape and the atmospheric changes are much the same in the two countries, both inland and on their rock-bound and storm-swept shores. IN SCOTLAND In the moorlands between Trossachs and Aberfoyle, a region made famous by Scott's _Rob Roy_, I have seen atmospheric changes so sudden and so contrasted as to appear marvellous. What shifting of vapours and clouds, what flashes of bright sun-gleams, then twilight at midday! Across the landscape, shadows of black dense fog-banks rush like shadows of flocks of great birds which darken all the earth. Palpitating fog-banks wrap themselves around the mountain-tops and then come down like living things to move across the valleys, sometimes only a few yards above the traveller's head. And in that country live terrible water-kelpies. When black clouds discharge their watery burden it is in wind-driven vertical water-sheets through which the world appears as through an ice-filmed window-pane. Perhaps in a single day there may be the bluest of heavens and the clearest air, the densest clouds and the darkest shadows, the calm of the morning and the wind of the tempest. At night in Aberfoyle after such a day, I witnessed a clear sunset and a fair evening sky; in the morning when I arose, the lowlands along the river were inundated and a thousand cascades, large and small, were leaping down the mountain-highlands, and rain was falling in heavy masses. Within an hour afterwards, as I travelled on towards Stirling, the rain and wind ceased, and there settled down over all the land cloud-masses so inky-black that they seemed like the fancies of some horrible dream. Then like massed armies they began to move to their mountain-strongholds, and stood there; while from the east came perfect weather and a flood of brilliant sunshine.