Among my first passions was that for exploration. The Unknown—that region of mysteries lying upon the outskirts of commonplace environment—drew me with a mighty attraction. My earliest recollections are of wanderings into the domains of the neighbors, and of excursions—not infrequently in direct contravention to parental warnings—over fences, stone-walls, and roofs, and into cobwebbed attics, fragrant hay-lofts, and swaying tree-tops. Of my favorite tree, a sugar maple, I remember that, so thoroughly did I come to know every one of its branches, I could climb up or down unhesitatingly with eyes shut. At that advanced stage of acquaintance, however, it followed naturally that the mysteriousness, and hence the subtle attractiveness, of my friend the maple was considerably lessened.