Vitrified Forts – Up In Smoke

Up In Smoke

When discussing Vitrified Hill Forts academics have a tendency to emit a lot of hot air and behave as if they were suffering from Smoke Inhalation.

Smoke inhalation is the primary cause of death for victims of indoor fires.

Smoke inhalation injury refers to injury due to inhalation or exposure to hot gaseous products of combustion.

Symptoms range from coughing and vomiting to nausea, sleepiness and confusion.

Once upon a time academics associated Vitrified Hill Forts with “battle damage”.

Battle damage is also unlikely to be the cause, as the walls are thought to have been subjected to carefully maintained fires to ensure they were hot enough for vitrification to take place.

In 1937 Vere Childe and Wallace Thorneycroft put the theory to the test at Plean Colliery in Stirlingshire by building a small wall using the Murus Gallicus construction technique.

Murus Gallicus

The Experimental Production of The Phenomena Distinctive of Vitrified Forts.
V. G. Childe and Wallace Thorneycroft
Proceedings of The Society, December 13, 1937

Murus Gallicus or Gallic Wall is a method of construction of defensive walls used to protect Iron Age hillforts and oppida of the La Tene period in Western Europe.

The distinctive features are:

● earth or rubble fill
● transverse cross beams at approximately 2 ft (60 cm) intervals
● longitudinal timbers laid on the cross beams and attached with mortice joints, nails, or iron spikes through augered holes
● outer stone facing
● cross beams protruding through the stone facing

However, to make sure the experiment had a sporting chance the defensive wall was laced with 1.3 tons of dry wood and filled with basalt broken into 2 inch cubes.

Then [to emulate battle conditions] 4 tons of timber and brushwood were carefully heaped [6 feet high and 3 feet thick] around the wall before it was torched.

The experiment produced a pile of vitrified rampart rubble but Childe and Thorneycroft noted highly silicious rocks [such as Carboniferous Sandstones] would not have been fused in the experiment.

In their closing comments Childe and Thorneycroft left academia to ponder whether their technique for producing a pile of vitrified rampart rubble could be “imitated to produce the more or less vertical faces of vitrified material” observed at Goat Island and Tap o’ Noth”.

Childe and Thorneycroft were very gentle when they broke the bad news to academia.

Undaunted, the academic vogue simply moved on to wall strengthening.

Some antiquarians have argued that it was done to strengthen the wall, but the heating actually weakens the structure.

This time it was left to Ian Ralston to break the bad news on national television in 1980.

Experimental firing of a full-scale model of a pine-laced wall provoked limited localized vitrification of the hearting.

The results may be added to previously-garnered evidence to refute the suggestion that vitrification was constructional in intent.

The large-scale vitrification of some Scottish sites must have provided a spectacular intimation of destructive power.

1980 Wall

During late March and early April 1980, a timber-laced wall, corresponding approximately to a later prehistoric type, was reconstructed on the margin of the City of Aberdeen District Council Cleansing Department’s waste disposal tip at Tullos Hill, Aberdeen City District, with a view to attempting to reproduce experimentally the characteristics of the vitrified walls recorded in north Britain.

The Yorkshire Television vitrified wall experiment at East Tullos, City of Aberdeen District
Ian Ralston – Proc SocAntiq Scot, 116 (1986), 17-40

Scotlands vitrified hill forts

Still undaunted, academia simply invoked ritual vitrification.

It is not clear why or how the walls were subjected to vitrification.

Most archaeologists now consider that vitrified forts are the product of deliberate destruction either following the capture of the site by an enemy force or by the occupants at the end of its active life as an act of ritual closure.

I guess it’s a lot easier speculating about ritualised vitrification than confronting “the more or less vertical faces of vitrified material” found on Goat Island which boasts two vitrified forts and no trees.

Goat Island

And I guess it’s a bit of a downer confronting vitrified walls four feet thick where the “vitrifaction has penetrated to the centre” when you’re suffering from smoke inhalation.

The district in which Dun Mac Uisneachan stands is between two lochs – Creran and Etive.

It is almost inaccessible except by water, and no doubt was once quite so, except to the best Highland feet.

It was therefore a safe point of settlement for any one coming from the sea, – safer than Dunstaffnage, although not so convenient for attacks inland.

The range of vision is great, extending seaward to Colonsay, and embracing capes and islands between, giving an aspect, as it were, of a bay, narrow, but forty miles in length.

Dun Macuisneachan View

The Dun is an isolated rock (see Plate VII.), one end rugged and washed by the sea ; the other, inland, is lower ; of clay slate and conglomerate.

The highest point is 150 feet above the sea.

It is divided into two very distinct parts, that next the sea being largest and highest.

There is a depression between, and in the depression a small elevation.

Dun Macuisneachan

The vitrified walls surround both divisions ; the largest shows a covered wall with the end exposed about 6 feet high and 4 feet broad.

I did not measure it ; it was difficult to do so, as the grass has overgrown nearly all, and it is at almost all points in appearance a mere elongated mound, the end sharply cut down.

The exposed part looks, however, more like a portion of a regular wall than those I have since seen elsewhere, and it seems surprising that its object could be doubted by any one.

The vitrifaction has penetrated to the centre, yet I did not see in any parts pieces of charcoal, although there were marks on one place which resembled the impression made by burnt wood.

It was easy to trace the wall, although covered with grass, and but little raised above the rest of the turf.

Everywhere, when the turf was removed, the vitrified masses appeared.

A large quantity had fallen down the precipitous sides, and from that portion specimens were generally taken by tourists.

Descriptive list of antiquities near Loch Etive, Argyllshire
Robert Angus Smith – Society of Antiquaries of Scotland – 1872

Dun Macuisneachan Plan

Loch Etive and the Sons of Uisnach – Robert Angus Smith – 1885

Site Name ‘Beregonium’, Benderloch

Classification Settlement (possible)

The RCAHMS states that the spurious name ‘Beregonium’, a mis-reading of Ptolemy’s ‘Rerigonium’, was mistakenly applied by Hector Boece in his ‘Scotorum Historiae’.

Coordinates: 56°29′32″N 05°24′13″W

Benderloch (Scottish Gaelic: Meadarloch) is a village in Argyll and Bute, Scotland.

The name is derived from Beinn eadar dà loch, meaning “mountain between two lochs”.


St Modan's Church - Benderloch

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