Washington Irving was so thoroughly versed in the lore of buried treasure that the necromancy of the divining rod, as a potent aid to this kind of industry, had received his studious attention. For many centuries, the magic wand of hazel, or various other woods, has been used, and implicitly believed in, as a guide to the whereabouts of secrets hidden underground, whether of running water, veins of metal, or buried treasure. There is nothing far-fetched, or contrary to the fact, in the lively picture of Dr. Knipperhausen, that experienced magician, who helped Wolfert Webber seek the treasure concealed by pirates on the Manhattan Island of the Knickerbocker Dutch of the "Tales of a Traveler." "He had passed some years of his youth among the Harz mountains of Germany, and had derived much valuable instruction from the miners, touching the mode of seeking treasure buried in the earth. He had prosecuted his studies also under a traveling sage who united the mysteries of medicine with magic and legerdemain. His mind therefore had become stored with all kinds of mystic lore; he had dabbled a little in astrology, alchemy, divination; knew how to detect stolen money, and to tell where springs of water lay hidden; in a word, by the dark nature of his knowledge he had acquired the name of the High-German-Doctor, which is pretty nearly equivalent to that of necromancer. "The doctor had often heard rumors of treasure being buried in various parts of the island, and had long been anxious to get on the traces of it. No sooner were Wolfert's waking and sleeping vagaries confided to him, than he beheld in them confirmed symptoms of a case of money digging, and lost no time in probing it to the bottom. Wolfert had long been sorely oppressed in mind by the golden secret, and as a family physician is a kind of father confessor, he was glad of any opportunity of unburdening himself. So far from curing, the doctor caught the malady from his patient. The circumstances unfolded to him awakened all his cupidity; he had not a doubt of money being buried somewhere in the neighborhood of the mysterious crosses and offered to join Wolfert in the search. "He informed him that much secrecy and caution must be observed in enterprises of this kind; that money is only to be digged for at night; with certain forms and ceremonies, and burning of drugs; the repeating of mystic words, and above all, that the seekers must first be provided with a divining rod, which had the wonderful property of pointing to the very spot on the surface of the earth under which treasure lay hidden. As the doctor had given much of his mind to these matters, he charged himself with all the necessary preparations, and, as the quarter of the moon was propitious, he undertook to have the divining rod ready by a certain night.