COMPARATIVE ARCHAOLOGY. 167 
Fronting the main entrance there was another doorway lead- 
ing to a central chamber, 15 feet in diameter, which had two 
or three niches in the surrounding solid wall. The roof of the 
central chamber, as well as the roofs of al] the smaller cham- 
bers and stair spaces, was formed on the principle of the bee- 
hive dome. Many of these towers, especially the more re- 
cently constructed, had around them a complicated mass of 
outworks, all constructed on the same general principle as 
the main building. 
Remains of some 6000 of these unique structures have 
been fairly distributed over the whole island of Sar- 
dinia, except on its north-east corner, where they are rarely 
met with. They were judiciously situated at the approaches 
‘to fertile tracts of land, near springs, and in the vicinity of 
river fords; but always within signalling distances of each 
other. The relics found on their ruins are of a domestic char- 
acter, such as household pottery, oil jars, étc. Arrow heads 
made of obsidian—a substance found in situ only in one place 
‘in the island—are found scattered over the country. A con- 
sensus of authoritative opinion now regards the nuraghi as 
fortified habitations, and not temples or tombs, as formerly 
conjectured. In their near vicinity some giant graves of a 
peculiar type have been explored, and are supposed to be the 
family burial places of the inhabitants of the nuraghi. These 
tombs are constructed in the form of elongated alleés cou- 
vertes, and have in front of the entrance a semi-circular double- 
lined stone wall, reminding one of the Horned chambers of 
Caithness and others in the midland counties of England. 
Fergusson (Rude Stone Monuments) described the nuraghi 
as absolutely peculiar to the island of Sardinia, and could find 
nothing like them, except the Talyots of the Balearic Islands, 
to which they have some structural resemblance. 
Brocus.—In Scotland we have a class of dry stone built 
monuments known as Brochs, or Pictish Towers, which in 
structure, function, and restricted distribution, have so many 
points in common with the nuraghi that both must be held as 
derivatives from the same architectural source. They are 
found distributed over a well-defined geographical portion of 
North Britain. Before they fell into ruins, some 400 might 
