A dolmen, it may be here explained, is a kind of chamber composed of upright unhewn stones, and roofed generally with a single huge stone. They are usually wedge-shaped in plan, and traces of a porch or vestibule can often be noticed. The primary intention of the dolmen was to represent a house or dwelling-place for the dead. A cromlech (often confused in popular language with the dolmen) is properly a circular arrangement of standing stones, often with a dolmen in their midst. It is believed that most if not all of the now exposed dolmens were originally covered with a great mound of earth or of smaller stones. Sometimes, as in the illustration we give from Carnac, in Brittany, great avenues or alignments are formed of single upright stones, and these, no doubt, had some purpose connected with the ritual of worship carried on in the locality. The later megalithic monuments, as at Stonehenge, may be of dressed stone, but in all cases their rudeness of construction, the absence of any sculpturing (except for patterns or symbols incised on the surface), the evident aim at creating a powerful impression by the brute strength of huge monolithic masses, as well as certain subsidiary features in their design which shall be described later on, give these megalithic monuments a curious family likeness and mark them out from the chambered tombs of the early Greeks, of the Egyptians, and of other more advanced races. The dolmens proper gave place in the end to great chambered mounds or tumuli, as at New Grange, which we also reckon as belonging to the Megalithic People. They are a natural development of the dolmen. The early dolmen-builders were in the neolithic stage of culture, their weapons were of polished stone. But in the tumuli not only stone, but also bronze, and even iron, instruments are found—at first evidently importations, but afterwards of local manufacture. *Origin of the Megalithic People* [Prehistoric Tumulus at New Grange] Prehistoric Tumulus at New Grange Photograph by R. Welch, Belfast