In June, 1908, after a year's preparatory work in things Celtic under the direction of the Oxford Professor of Celtic, Sir John Rhŷs, I began to travel in Wales, Ireland, Scotland, and Brittany, and to collect material there at first hand from the people who have shaped and who still keep alive the Fairy-Faith; and during the year 1909-10 fresh folk-lore expeditions were made into Brittany, Ireland, and Wales, and then, finally, the study of the Fairy-Faith was made pan-Celtic by similar expeditions throughout the Isle of Man, and into Cornwall. Many of the most remote parts of these lands were visited; and often there was no other plan to adopt, or any method better, or more natural, than to walk day after day from one straw-thatched cottage to another, living on the simple wholesome food of the peasants. Sometimes there was the picturesque mountain-road to climb, sometimes the route lay through marshy peat-lands, or across a rolling grass-covered country; and with each change of landscape came some new thought and some new impression of the Celtic life, or perhaps some new description of a fairy. This immersion in the most striking natural and social environment of the Celtic race, gave me an insight into the mind, the religion, the mysticism, and the very heart of the Celt himself, such as no mere study in libraries ever could do. I tried to see the world as he does; I participated in his innermost thoughts about the great problem of life and death, with which he of all peoples is most deeply concerned; and thus he revealed to me the source of his highest ideals and inspirations. I daily felt the deep and innate seriousness of his ancestral nature; and, living as he lives, I tried in all ways to be like him. I was particularly qualified for such an undertaking: partly Celtic myself by blood and perhaps largely so by temperament, I found it easy to sympathize with the Celt and with his environments. Further, being by birth an American, I was in many places privileged to enter where an Englishman, or a non-Celt of Europe would not be; and my education under the free ideals of a new-world democracy always made it possible for me to view economic, political, religious, and racial questions in Celtic lands apart from the European point of view, and without the European prejudices which are so numerous and so greatly to be regretted. But without any doubt, during my sojourn, extending over three years, among the Celts, these various environments shaped my thoughts about fairies and Fairyland--as they ought to have done if truth is ever to be reached by research.