The theory was a tremendous affair, having to do with nothing less than the formation of our continent. It was revolutionary in the extreme, but shed such illumination in hitherto dark corners of this and allied subjects that its probability, _prima facie_, was practically assured. To Prue Welch it seemed to be quite so; but the inexorable eye of science discerned breaks in the chain of continuity, gaps in the procession of proofs, which, while not of vast importance in a specious argument designed to furnish with peptonized intellectual pabulum the more frivolous-minded layman, nevertheless sufficed to destroy utterly its worth as a serious hypothesis. These breaks, the professor explained, could never be filled except by actual field-work. The proper field, he assured her, was the country of the Black Hills of South Dakota, then as distant as the antipodes. He proved this scientifically. Prue agreed, but did not understand. A number of years later she did understand, from hearing Billy Knapp joking with Alfred. "These yar hills," said Billy, "was made last. The Lo'd had a little of everything left when he'd finished the rest, so he chucked it down on the prairie, an' called it the Black Hills." However, the mere fact of her comprehension mattered not one iota. If Adoniram said a thing was so, to Prue its truth at once became age-old. So it happened that the great theory hung fire wofully, and the country of their dreams came to lie beyond the frontier wilderness, whose tide was but just beginning to ebb back from the pine woods of Wisconsin and the oak openings of Illinois. This was finality. What lay beyond they did not trouble to inquire. The professor sighed the sigh of patient abnegation. The professor's wife believed, with beautiful trust, that a divine providence would provide, and that with the earth-wide fame that must accrue to the author of _New World Erosions_ would come added opportunity for added reputation. For a number of years the kind-hearted little professor looked steadfastly out of the window during examinations in geology, and turned a resolute deaf ear to the rustling of leaves as the despairing student manipulated a cleverly concealed volume. For a number of years he came home at four o'clock in the afternoon, and feverishly corrected blue books until six, in order to ransom from professional duties the whole of the precious evening. For a number of years he consulted authorities in German and other difficult languages, and waxed ever more enthusiastic over the new theory of erosions. During the interim the baby learned to walk, and Prue's belief in its father strengthened, if such a thing were possible. In time the professor and his wife grew to be quite old. He looked every bit of his thirty, and she was an aged dowager of twenty-five. Little Miss Prue was just two and a half.