to a peculiar class of structures, all radically alike, and all known, in certain districts, as "Picts' houses." The term "Picts' house" is unknown in the Hebrides, says one writer. "In the Hebrides tradition is entirely silent concerning the Picts ... there the Fenian heroes are the builders of the duns."[49] Yet the self-same class of building is elsewhere assigned to the Picts. To these structures I shall presently refer more particularly; but it is enough to note in passing that, just as Oisin, King of the Fians, is translated into Ossian, King of the Picts, so the dwellings ascribed to the Fians in one locality, are in another said to have been made and inhabited by the Picts. Fians, then, are associated or identified with Fairies, and also with Picts. To complete my equilateral triangle, the Picts ought also to be regarded as Fairies, or as akin to them. This undoubtedly is a popular belief. The earliest alleged reference of this kind is placed by one writer in the middle of the fifteenth century, before the Orkney Islands had passed from the crown of Denmark to the crown of Scotland. A manuscript of the then Bishop of Orkney, dated Kirkwall 1443, states that when Harald Haarfagr conquered the Orkneys in the ninth century, the inhabitants were the two "nations" of the _Papæ_ and the _Peti_, both of whom were exterminated. By the former name is understood the Irish missionaries: the _Peti_ were certainly the Picts, or Pehts.[50] Now, of these Picts of Orkney it is said, that they "were only a little exceeding pigmies in stature, and worked wonderfully in the construction of their cities, evening and morning, but in mid-day, being quite destitute of strength, they hid themselves through fear in little houses under ground."[51]