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The broch of Mousa: by kind permission of David Simpson. |
Mousa
is a small island off the coast of mainland Shetland with a Norse name.
The 'a' at the end, as in many British place-names, means 'island.'
'Mous' means 'mossy.'
The
'Mousa boat' ferries you across to the moss. It's a nature reserve now,
and well worth visiting for the birds and seals alone. But what I
wanted to see -- what I'd wanted to see for years -- was the Broch of
Mousa. It did not disappoint.
The
first glimpse of the broch is a striking: a monumental tower, against
sky and sea, its walls gently curving like those of a modern cooling
tower.
Amazement only grows from there.
To consider place-names again, the word ‘broch’ is the same as the ‘borough’ or ‘bury’. It means ‘fortified place’ or ‘castle.’ Archaeologists adopted the Scottish form ‘broch’ as a name for the ‘towers in the north,’ the dry-stone, ancient towers found all over Scotland and only in Scotland.It’s
impossible to accurately date these mysterious towers though it’s
broadly agreed that they are ‘Iron Age’ and the oldest may be as much as
three thousand years old— but Maeshowe, in Orkney, shows that there was a strong tradition of building dry-stone corbelled structures, going back five thousand years. (A
corbelled roof is where dry-stone slabs are skilfully overlapped to
form a smooth, inward curving roof sealed with a single cap-stone.)
Above,
the interior of the passage-grave, Maeshowe, on Orkney, showing its
smooth, inward curving, corbelled ceiling. It is acknowledged as 'the finest Neolithic building surviving in north-west Europe.'
The main building is estimated to be at least 5000 years old, making it
older than the pyramids. Its entrance is aligned to the setting sun at
the midwinter solstice.
The
immense, upright stone slabs at the corners have no constructive
purpose at all. They are not holding up the roof or supporting the walls
as you might think. They were already in place before Maeshowe was
built. The grave was built around them, as if to preserve or honour
them. Possibly they were standing stones. Perhaps the remains of another
house or grave. I don't know about you, but this makes my brain boggle.
Mousa’s broch is the most complete of all brochs, still standing 13m (42/43 feet) high. Its
twin, the broch of Burraland, which stood on the other side of the
strait between Mousa and mainland Shetland, was ‘robbed out’ for
building stone and is now only 2-5 metres (8 feet) high. It's
sometimes suggested that Mousa's broch was protected from destruction by
its position on a small island -- even though Mousa was home to
stone-hungry crofters until the 19th century.
Mousa’s
excellent preservation tempts us to take it as a model for all brochs
but archaeology shows that Mousa is very untypical. It’s quite small,
underwent considerable alteration in antiquity and, overall, is much
better built than your average broch. Its superior construction may have
been its salvation: it was simply harder to dismantle than other
brochs. Whatever preserved it, there’s no doubt it deserves its status
as a World Heritage Site.
To give a simple account of the broch’s interior:
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Inside the broch of Mousa: copyright: David Simpson.There
are no windows in the outer wall and only one entrance, facing the sea.
This entrance is 1-5 metres (5 ft) high and the passage behind it is 5
metres (16ft) long. At the end of the passage a ‘bar-hole’ can be seen
in the wall. This is where a solid wooden 'bar' would have been put in
place, to prevent the door being opened from outside. Whoever lived --
or took shelter -- within these massive walls was keen on some other
people staying outside. The
entrance passage opens into a roughly circular space. At its centre is a
hearth and a stone water-tank, reminiscent of the five thousand year
old neolithic houses at Orkney’s Skara Brae. Although
the outer circumference of Mousa Broch is 15m (45ft), the interior is
only 6m (19-20ft) in diameter.
Built into the massive base of the broch are three large corbelled
cells, differing slightly in size. The largest is about 1-5 metres (5ft)
wide, 4 meters (13ft) long and 3 metres (11 ft) high. The doors into
these cells are raised above the floor of the broch, perhaps to keep out
draughts. Each also has a built-in shelf— again, like Skara Brae, where
the bed-spaces had shelves built into the walls beside them. The
walls above the cell-doors have gaps or windows constructed into them,
possibly to lighten the load each lintel has to bear and to allow light
into the cells. Modern houses can have rooms smaller than these without the storage. Mousa's
tower is double-skinned, with a ring of outer wall, a ring of inner
wall and a gap between them. The outer and inner walls are pinned
together with slabs of slate.
In this way ‘galleries’ were formed between the walls. It's possible,
with some stooping and squeezing, to walk along these galleries to their
blind ends. At other brochs, at least where enough of these galleries
remain to judge, it isn't. They are too low and too much stone protrudes
into them. These galleries are due to Mousa broch's method of construction: the twin walls were built up to a certain height, then slates were used to bridge the gap between them; and then the walls were built higher and 'pinned' again. The galleries weren't intended to be lived in, or to be used as storage -- but all the same, I'd guess that they were so used, at least to some extent. The broch's
builders used the gap between the walls and the pinning slabs to make
an interior stair which winds inside the walls right to the top of the
tower. (The hand-rail is modern.)
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Beyond this, much is conjecture.
For
instance, the inner wall was constructed with tall rows of gaps,
(giving ancient Mousa a startlingly modern ‘architectural’ look.) It’s
often argued that these were to ‘light the stairwell’ and the corbelled cells, which they
certainly do today because now the tower is roofless. Perhaps it was
roofed somehow, in the past, and the purpose of the 'gaps' was to reduce
weight on the walls?
Roofed or Open?
There
are endless arguments about what the summit of the broch was originally
like. The top was somewhat reconstructed -- with guesswork -- in the
1960s and '80s, so that now you can walk around on top, admiring the
view. But no one knows for certain what the top of the broch was like when first built.
Some
argue that there was no walkway and that the broch was always open to
the weather, as now, allowing the rain and snow to fall down between the
concentric walls.
Another
argument insists that the broch was roofed somehow, though no one can quite figure out how. Maybe the gap
between the walls was turfed or thatched, leaving the courtyard open...
Maybe the whole top of the broch was covered by a conical thatch, making the broch look like a very tall Iron Age roundhouse.
Stretch!
The Open-to-the-Sky mob reply that the weight of the supporting timbers, plus
thatch, pressing
outward against the walls would make this unlikely. Also, it would make
the broch's interior impenetrably dark. (True, but many houses in the
past were windowless and dark. Viking longhouses, for instance.
Inhabitants spent much of the day outside and, at night, there was fire
and lamplight.)
It's
a conundrum. About the roof, I'm neutral but think there must have been
some kind of platform up the top there. Why go to the enormous effort
of building a dry-stone tower that may, originally,
have been more than fifteen metres high (49 ft) , with a stair climbing all the way to the top, if not to stand up there and see further than from ground level?
More Conjecture
At some point in antiquity, a stone wheelhouse
was built inside the stone tower. The hearthstone and water tank belong
to this wheelhouse, as does the wide stone ‘bench’ that runs around the
inside of the tower. (You can see the 'bench' or wall in the photo of
the interior above, running around the wall towards the left,)
The
builders of the stone wheelhouse continued to use the broch's corbelled
cells, because they left gaps in their own stone wall, to allow them
entrance. But they built across the entrance to the broch's stairs and
galleries, blocking them off. Obviously, they had no love of a sea-view
or a need to know who was approaching.
It
was possibly around the time this inner wheelhouse was built that the
broch’s entrance was altered, making it much larger. This also meant
breaking through the floor of a corbelled cell built above the entrance.
(This cell must originally have been entered via the stairs and some
kind of upper floor. There are also endless arguments about how this
upper floor may have been built into the broch.)
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Dun Carloway, Lewis: by permission of David Simpson |
By
making Mousa's entrance larger, it was also made less defensive
than
the entrances of other brochs, such as Dun Carloway on Lewis, where the
doorway is much smaller and narrower.
Why
were the brochs built? The theory favoured in the 19th Century was that
they were defensive ‘castles.’ Hence their name: 'broch, a fortified place.' Then, in the 'Peace and Love' of the 1960s and 70s, it became fashionable to say that they weren’t
defensive because they couldn’t have withstood a determined attack. No,
they were merely the prestigious houses of a ruling elite.
Brochs
have tall, thick walls, entirely windowless on the outside. Most
brochs, unlike Mousa, have low narrow doors, that make you stoop double
to enter. Yet the builders could make corbelled ‘cells’ 3 metres high,
so the entrances weren’t low for ease of building. They could construct
windows too, so the outer walls were deliberately made without openings.
Behind
the entrance, brochs have long, low, easily defended passages with
doors which could be strongly barred. None of this speaks to me of an elite’s
comfort. It positively screams ‘defensive’.
If a broch couldn’t have withstood a determined attack, neither could the later pele towers of the Borders but no one doubts they were
defensive. Rather than withstand ‘determined attack' the peles were
meant to discourage attack from largely opportunistic bands of reivers. They said: 'We're ready for you and you won't have it easy.'
The
reivers were some three thousand years later but human nature stays
much the same. Why invest so much time and effort into building a broch
unless there’s somebody around who scares you? People capable of
building a broch could, if they'd wished, have built something equally impressive and much
more comfortable.
Who
were the scary people? Unruly neighbours or passing armies, as with
the reivers? Other commentators favour the idea that it was the Romans—
but some brochs were probably built long before any possible appearance
of any Roman ships off the Scottish coast.
Again, the truth is, no one knows -- which leads to many more fun arguments? Castles? Manor-houses? Cathedrals?
Many
brochs seem to have had clusters of much smaller wheelhouses around
them -- there are faint traces at Mousa. This might support the manor-house theory or make the broch a place of refuge during raids. Did they, like the peles, have a signalling
beacon on top? Or were they look-out towers, watching for danger
approaching from land or sea?
The
majority of brochs are near the sea. Mousa, and the Burraland broch had
views up and down the Shetland coast. Dun Carloway stands near a
natural harbour on Lewis. During the time they were built, we know there
was trade between Ireland and the islands -- and with what was
then not yet England.
A
natural harbour often becomes a market-place. Prosperous markets
attract thieves and ‘trade’ easily turns into ‘raid’ and slave-taking.
If a market town wants to keep its trade, it has to provide protection.
Were the brochs garrisons and look-out towers, protecting a market?
In reality, the
brochs may have had several purposes: defensive, if need be, but also
providing advance warning of the approach of ships, for good or ill.
They discouraged attacks by loudly declaring in stone: ‘We’re ready for
you.’
All of which may be nonsense. Perhaps they were very
expensive and uncomfortable prestige homes for the Iron Age plutocrat.
What is without question is that they are astonishing feats of ancient
ingenuity and engineering. Anyone who thinks the pre-Roman inhabitants of
these islands were 'unsophisticated' should visit the
Broch of Mousa.
And Maeshowe.
And Skara Brae.
Follow this link for a short video tour of Mousa Broch.
And if you're interested in more discussion about how, or if, the broch was roofed and what exactly it was used for, follow this link