ONE evening in midsummer, nearly five hundred years ago, a stranger arrived in the quaint old town of Haarlem, in the Netherlands. The people eyed him curiously as he trudged down the main street, and there were many guesses as to who he might be. A traveler in those days was a rarity in Haarlem—a thing to be looked at and talked about. This traveler was certainly a man of no great consequence. He was dressed poorly, and had n