chitecture and found that the same features are noticeable
in all countries where these buildings occur. In each case we see a type
of construction based on the use of large orthostatic slabs, sometimes
surmounted by courses of horizontal masonry, with either a roof of
horizontal slabs or a corbelled vault. Associated with this we
frequently find the hewing of underground chambers in the rock. In
almost all countries where megalithic structures occur certain fixed
types prevail; the dolmen is the most general of these, and it is clear
that many of the other forms are simply developments of this. The
occurrence of structures with a hole in one of the walls and of blocks
with 'cup-markings' is usual over the whole of the megalithic area.
There are even more remarkable resemblances in detail between structures
in widely separated countries. Thus the Giants' Tombs of Sardinia all
have a concave facade which forms a kind of semicircular court in front
of the entrance to the tomb. This feature is seen also in the temples of
Malta, in the tomb of Los Millares in Spain, in the _naus_ of the
Balearic Isles (where, however, the curve is slight), in the Giant's
Grave of Annaclochmullin and the chambered cairn of Newbliss in Ireland,
in the tomb of Cashtal-yn-Ard in the Isle of Man, in the barrow of West
Tump in Gloucestershire, and in the horned cairns of the north of
Scotland. These parallels are due to something more than coincidence; in
fact, it is clear that megalithic building is a widespread and
homogeneous system, which, despite local differences, always preserves
certain common features pointing to a single origin. It is thus
difficult to accept the suggestion that it is merely a phase through
which many races have passed. The phases which occur in many races alike
are always those which are natural and necessary in the development of a
people, such as the phase of using copper. But there is nothing either
natural or necessary in the use of huge unwieldy blocks of stone where
much smaller ones would have sufficed.

There are further objections to this theory in the distribution of the
megalithic buildings both in space and time. In space they occupy a very
remarkable position along a vast sea-board which includes the
Mediterranean coast of Africa and the Atlantic coast of Europe. In other
words, they lie entirely along a natural sea route. It is more than
accident that the many places in which, according to this theory, the