Structures
Brochs vary from 5 to 15 metres (16–50 ft) in internal diameter, with 3 metre (10 ft) thick walls. On average, the walls only survive to a few metres. There are five extant examples of towers with significantly higher walls: Dun Carloway on Lewis, Dun Telve and Dun Troddan in Glenelg, Mousa in Shetland and Dun Dornaigil in Sutherland, all of whose walls exceed 6.5 m (21 ft) in height. Mousa's walls are the best preserved and are still 13 m tall; it is not clear how many brochs originally stood this high. A frequent characteristic is that the walls are galleried (the outer and inner wall skins are separate but tied together with linking stone slabs, with an open space between). These linking slabs may in some cases have served as steps to higher floors. Beside the door, it is normal for there to be a cell breaking off from the passage; this is known as the guard cell. It has been found in some Shetland brochs that guard cells in entrance passageways are close to large door-check stones. Though there was much argument in the past, it is now generally accepted that brochs were roofed, probably with a conical timber framed roof covered with a locally sourced thatch. The evidence for this assertion is still fairly scanty, though excavations at Dun Bharabhat, Lewis, have supported it. The main difficulty with this interpretation continues to be the potential source of structural timber, though bog and driftwood may have been plentiful sources.
On the islands of Orkney and Shetland there are very few cells at ground floor. Most brochs have scarcements (ledges) which would have allowed the construction of a very sturdy wooden first floor (first spotted by the antiquary George Low in Shetland in 1774), and excavations at Loch na Berie on the Isle of Lewis show signs of a further, second floor (e.g. stairs on the first floor, which head upwards). Some brochs such as Dun Dornaigill and Culswick in Shetland have unusual triangular lintels above the entrance door.
As in the case of Old Scatness in Shetland (near Jarlshof and Burroughston on Shapinsay, brochs were sometimes located close to arable land and a source of water (some have wells or natural springs rising within their central space). Sometimes, on the other hand, they were sited in wilderness areas (e.g. Levenwick and Culswick in Shetland, Castle Cole in Sutherland). Brochs are often built beside the sea (Carn Liath, Sutherland); sometimes they are on islands in lochs (e.g. Clickimin in Shetland).
About 20 Orcadian broch sites include small settlements of stone buildings surrounding the main tower. Examples include Howe, near Stromness, Gurness Broch in the north west of Mainland, Orkney, Midhowe on Rousay and Lingro near Kirkwall (destroyed in the 1980s). There are "broch village" sites in Caithness, but elsewhere they are unknown.
Most brochs are unexcavated. Many of those that have been properly examined show that they continued in use for many centuries, although the interiors were often modified and changed, and they underwent many phases of habitation and abandonment. The end of the broch period par excellence seems to have come around AD 200-300.
Read more about this topic: Broch
Famous quotes containing the word structures:
“The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.”
—Friedrich Nietzsche (1844–1900)
“It is clear that all verbal structures with meaning are verbal imitations of that elusive psychological and physiological process known as thought, a process stumbling through emotional entanglements, sudden irrational convictions, involuntary gleams of insight, rationalized prejudices, and blocks of panic and inertia, finally to reach a completely incommunicable intuition.”
—Northrop Frye (b. 1912)
“If there are people who feel that God wants them to change the structures of society, that is something between them and their God. We must serve him in whatever way we are called. I am called to help the individual; to love each poor person. Not to deal with institutions. I am in no position to judge.”
—Mother Teresa (b. 1910)