COMPARATIVE ARCHAOLOGY. 169 
the ground floor, about the middle of which there is evidence 
to show that it had been protected by a stone door barred from 
within. In other brochs there is usually a guard-chamber 
on one or both sides of the entrance passage, constructed in 
the solid wall, after the manner of the beehive chambers.”’ 
The chief points of difference in these structures are (1) 
the central area of the broch was an open court: that of the 
nuraghe was a central chamber with a beehive roof. (2) The 
spiral stair in the former led to the top of the building, and in 
intersecting the galleries gave access to them: that in the 
latter also led to the top, as well as to a second chamber, 
provided there was a second storey in the tower. All the 
chambers in both buildings had been roofed on the beehive 
principle—a feature which alone shows more than a mere 
incidental connection. Beehive chambers, when constructed 
as huts in the open, are necessarily limited on architectural 
principles to small buildings only a few feet in diameter ; but 
when surrounded by an accumulation of stones or earth they 
are capable of attaining considerable dimensions. That 
known as the Treasury of Atreus, at Mycenae, measured 48 
feet in diameter and 48 feet in height. The invention of the 
beehive principle of roofing and arching dates back to Neo- 
lithic times; but on the spread of Christianity into Western 
Europe the beehive hut was found to be so well adapted to 
the simple wants of the early Christians that it was utilised 
for monastic cells. The most perfect example of the primi- 
tive Christian cashel now to be seen is on the island of Skellig 
Michel, on the south-west coast of Ireland, which contains a 
church, an oratory, and several beehive huts—some of the 
latter being still entire. 
Similar remarks as to the resemblances and differences 
between the different classes of megalithic monuments could 
“be greatly extended did space limits permit. Glancing at 
them as a whole, we see that while the British Isles are the 
home of the orthostatic Stone Circles, France claims that dis- 
tinction for the dolmens, the number of which is estimated at 
4000, distributed over 78 departments, and of this number 
there are no less than 618 in Brittany. The larger chambered 
cairns and tumuli had entrance passages, generally constructed 
