It is around the unknown and the unknowable in this world that terror and superstition mostly cling. Had any one invented the telegraph, the telephone, or any other of the wonders developed by a proper knowledge of the powers of electricity, three hundred years ago, ten to one that individual would have been condemned to the stake as being in league with the Evil One. We have all of us heard tell of or read about mermaids and mermen, but few perhaps of the cultivated believe in such beings nowadays. People in the far north of Scotland, especially those born and bred among the wild, weird mountains and glens, and the misty and awful gloom that often settles over these for days, are different. No wonder that in such localities ghosts are often said to be seen, and mournful cries are heard by night or while storms of wind and rain are raging. But it was more among the lone Hebrides that mermaids were believed in, and it is not so very long ago that an old laird lived who credited the notion that these semi-fairies had really been seen and heard. It remained, however, for the king of the gipsies, Biffins Lee, not only to see one, not only to capture one, but to exhibit the creature in a huge tank at the Queerest Show on Earth. It was many months before Antony Blake came north here to buy the beautiful saloon caravan 'Gipsy Queen,' and upon an evening in summer, when two fishermen were slowly pulling their boat across a rock-girt bay, that a mermaid suddenly appeared to them. The reader must understand that two sides of this deep-water bay are entirely walled in by precipitous rocks without any shore or beach big enough for even a bird to perch upon. When it was low-tide the water was still deep all along the base of these cliffs, for it simply rose against the rocks when the tide was in and fell again at low-water. The place where the strange being was seen to rise from the dark, watery depths was far away from any place from which a human being could have swam, except on the surface of the water. Hardly even a seal could have remained under long enough to have enabled it to swim to a distant point. But one boatman had clutched the other. He was pale as death with the fear that grasped his heart. 'Oh--look--John! lo--ok!'