Mr. Greenwell, in his “British Barrows,” says:--“The incompleteness of these circles is so frequent a feature in their construction that it cannot be accidental. They have, moreover, been left incomplete in some cases in a way which most evidently shows a design in the operation; as, for instance, where the circle is formed of a number of stones standing apart from each other. The space between two of them has frequently been carefully built up with one large or several smaller stones. The effect of this is to break the continuity, or rather the uniformity, of the circle, and so to make it imperfect. This very remarkable feature in connection with the enclosing circles is also found to occur in the case of other remains which belong to the same period and people as the barrows. The sculptured markings engraved upon rocks, and also upon stones forming the covers of urns or cists, consist in the main of two types, cup-shaped hollows, and circles, more or less in number, surrounding in most cases a central cup. In almost every instance the circle is imperfect, its continuity being sometimes broken by a duct leading out from the central cup; at other times by the hollowed line of the circle stopping short when about to join at each end. The connection of these sculptured stones, if so they may be termed, with places of sepulture, brings them at once into close relationship with the enclosing circles of barrows, and it is scarcely possible to imagine but that the same idea, whatever that may have been, is signified by the incomplete circle in both cases.”[47] [Illustration: _Fig. 47._--CINERARY URN WITH HOLES IN THE SIDE, FROM SALISBURY PLAIN.] The great inner ring of trilithons at Stonehenge affects the horse-shoe shape, and is, and always was, incomplete. The outer ring of trilithons is too ruinous for us to be able to state what its original condition was. The horse-shoe, the incomplete ring, is still regarded as lucky, and a protection against witches. The enchanter who raised spirits was wont to draw a complete circle around him, and the demons raged outside this circle, but could not pass within and hurt him who had conjured them up. If he stepped outside the circle, or broke the continuity of the ring, then the spirits entered and tore him to pieces. This probably gives us a clue to the signification of the incomplete circle. The complete circle confines a spirit within it, or protects from the entrance of spirits; an interrupted circle allows spirits to pass to and fro, gives ingress and egress. The tomb is the house of the dead. He lives in it after some mysterious, not clearly defined fashion. And as a bee-hive hut had its door, so must the hut of the dead have its door. It would be a cruelty to the dead to imprison him; and if the circle be complete, the dolmen closed in on all sides, he could not come in and out at pleasure.