From this ready sympathy came that rare faculty--seldom possessed by scholars--which made Professor Child peculiarly fit for his greatest task. Few persons understand the difficulties of ballad investigation. In no field of literature have the forger and the manipulator worked with greater vigor and success. From Percy's day to our own it has been thought an innocent device to publish a bit of one's own versifying, now and then, as an "old ballad" or an "ancient song." Often, too, a late stall-copy of a ballad, getting into oral circulation, has been innocently furnished to collectors as traditional matter. Mere learning will not guide an editor through these perplexities. What is needed is, in addition, a complete understanding of the "popular" genius, a sympathetic recognition of the traits that characterize oral literature wherever and in whatever degree they exist. This faculty, which even the folk has not retained, and which collectors living in ballad-singing and tale-telling times have often failed to acquire, was vouchsafed by nature herself to this sedentary scholar. In reality a kind of instinct, it had been so cultivated by long and loving study of the traditional literature of all nations that it had become wonderfully swift in its operations and almost infallible. A forged or retouched piece could not deceive him for a moment; he detected the slightest jar in the genuine ballad tone. He speaks in one place of certain writers "who would have been all the better historians for a little reading of romances." He was himself the better interpreter of the poetry of art for this keen sympathy with the poetry of nature. Constant association with the spirit of the folk did its part in maintaining, under the stress of unremitting study and research, that freshness and buoyancy of mind which was the wonder of all who met Professor Child for the first time, and the perpetual delight of his friends and associates. It is impossible to describe the charm of his familiar conversation. There was endless variety without effort. His peculiar humor, taking shape in a thousand felicities of thought and phrase that fell casually and as it were inevitably from his lips, exhilarated without reaction or fatigue. His lightest words were full of fruitful suggestion. Sudden strains of melancholy or high seriousness were followed, in a moment, by flashes of gaiety almost boyish. And pervading it all one felt the attraction of his personality and the goodness of his heart.