05 June, 2017

Hadrian’s Wall; milecastles, turrets and artillery

Problems; what problems? 
To the casual observer, what Hadrian’s Wall was for and how it worked is fairly straight forward, but dig a little deeper and all is not as it seems. 
If you accept the Wall as an exercise in military architecture and that warfare is ultimately about numbers, then the figures just don’t add up quite as you might expect.
 The “problem” is as much perceptual as academic, since it has long been patently obvious to serious study that the Wall “garrison” as represented by the milecastles and even the forts would be hard pressed to defend the wall in a conventional sense.  It would be fair to say that the Wall has been seen as much a base for counter-attacking the enemy as a barrier to be defended; with good early warning from outlying forts it was envisaged that decisive actions would have been to the north of the Wall.[1]
Thus, for reasons which I will discuss further below the way we view the Wall as physical barrier should not be taken for granted; I use the word “view” advisedly, since so little of the Wall survives, the way we “picture” the Wall, both objectively in its visual culture and subjectively in our own mind represents a “understanding” which profoundly influences our other forms of thinking.
My interest started with the proposition that the spacing of the milecastles and turrets at c. 540 yards [2] might be related to use artillery [balistas/ scorpio], which lead me to build a CAD model a model of milecastle, turret and connecting Wall.  I am now happy about the potential use of torsion bows, but other more widely accepted ideas expressed and illustrated in our visual culture of the Wall, do not make sense in terms of military architecture or strategy.
It is not a new problem, because it is the central issue of Hadrian’s Wall; put simply how was the Wall supposed to work in terms of military architecture?
The Plan
Leaving aside the subsequent changes, the initial plan for the “Broad Wall” was for curtain wall with gates every mile protected by a small fort or “milecastle”, with a garrison of about 40 -50, separated by two intervening small turrets.  By any standard this arrangement is lightly manned, and the classic model presumed that if attacked these garrisons would be reinforced from forts on or behind the wall [1], counter attacking via the many gates to trap the attacker against the Wall. The outlying forts on the major routes from the north would give warning to deploy troops to appropriate forward positions, particularly the main fighting legionary units of the army based to the south at York and Chester.
Thus, the Wall has been viewed more as base with the initial decision to punctuate the Wall with Gates every mile allowing complete freedom of movement into the areas north of the Wall.   The Wall provided a physical barrier that cannot readily be pulled down or burnt which would prevent horses, carts and to a lesser extent hostile troops crossing into the south; it was an expensive, but permanent solution. The only practical way through was to capture one of the gates controlled by a milecastle.
It is simply a question of force ratios; in convention military thinking the attacker needs a certain superiority of numbers in order to come a defended position, dependent on the nature of the position and the forces. 
Typically, attacker might require an advantage of 3:1 over the defender.
In this period Roman adversaries would deploy forces measures in tens of thousands, as Mons Graupius in 87 where Agricola faced 30,000 Caledonians.  While Roman forces fighting from defended positions were highly effective, garrisons of 40 or even 80 in the milecastle would be hard pressed if surprised by a force of thousands.   The chances of holding any mile of Wall even with reinforcements is hopelessly optimistic, given that anyone with a ladder could climb the Wall and envelope a milecastle.
The critical technology – the gates and associated tower, is well known and proven in Roman Fort which typically had four entrances, very different from Hillforts or castles.   Fortifications are entered and usually attacked via their gate, but the Fort by offering four possible places to attack, also forces the attacker to divide their forces to cover all the gates or risk being counter attacked by the garrison.
However, forts are a very different context; a typical legionary fortress like Caerleon has 4 gates and 30 turrets in curtain Wall perimeter of slightly over a mile in length; defended by a garrison of 4000 – 5000 of the best infantry.  Caesar describes how a Legion commanded by Cicero’s younger brother successfully held their fort against the Eburones uprising in the winter of 54–53 BC [3], [while a force of 15 cohorts who abandoned their camp were ambushed and massacred].
This is very different to the Wall, where Britain’s entire 3 legionary garrisons is only roughly equivalent to 180 men per mile or one every 30’; the curtain Wall is only defendable if you can get sufficient forces there fast enough.  Ultimately, it is the 10’ wide gaps in the Wall that are the key links in the chain, and the time taken by the enemy to capture a milecastle becomes the only important parameter.
Turrets as Artillery Platforms
The Roman’s use of torsion artillery was a unique capability in this theatre, which, given the small scale of garrisons, represents only realistic available methods of interdiction available from the milecastles or turrets. Thus, their spacing at roughly 540 yards could be related to the range of certain types of weapon.
Julius Caesar tells us of an incident where to prevent his troops being out flanked and enveloped by a larger force, Caesar creates, at right angles to his front, physical barriers covered by his artillery dug in at either end.
 “….on either side of that hill he drew a cross trench of about four hundred paces, and at the extremities of that trench built forts, and placed there his military engines…” [Caes. Gal.2.8]
What is significant here is distance between his artillery units, suggesting that some of his pieces had a range of 400 yards, which would allow mutual covering fire.
There is view that some engines had a range of up to c. 400 - 500 yards, which is supported by archaeological evidence from the Jewish wars. [4]  Excavation at Gamla besieged in 67AD  found that stone Balista shot of 2 -6 kg / 10 -16 cm was fired from positions 330 yards [300m] from town, shot being found up to 65 yards [60m] inside the defences.

The spacing of the turrets and milecastles at 540 yards is realistically too great provide mutual covering fire, however, while crossing the Wall in the middle between the turrets might seem the obvious choice for the attacker, it is the place is exposed to maximum crossfire.
Thus, in terms of artillery, the turrets were placed just far enough apart to be effective; by contrast sections of Caesar’s rampart at Alisia in 52bc, like the fort at Caerleon, had Turrets spaced every 27 yards, which is probably reflects the effective range of pilum in this context.

While artillery platforms are known from the area, [5], it has to be said that I am not aware of significant finds of bolts, stones, or other ammunition associated with the turrets or milecastles.   The argument might seem better if the towers were closer together, but it’s in keeping with general minimalistic approach to the layout of Wall.   

A Milecastle Model #1
Theoretical Structural Archaeology was developed for the complex problems presented by the foundations of timber buildings, but is equally applicable to the less ambiguous remains of stone walled structures. It attempts to model structures directly from the evidence of foundations,  independently of the visual culture or textual conventions of the period.  The engineering of buildings and other structures is governed by general rules, as well as the context specific conventions such as those found in military architecture.  In addressing the spatial evidence of the archaeological record it produces different results from research that simply considers the conventions of textual summery found in the Wall’s literary construct. 
Theoretical modelling, while not simulating the process of building, forces the modeller to take design decisions and follow through the consequences.  While it is possible to build a structure from individual randomised blocks, there is a law of diminishing returns, and any exercise in modelling is usually directed towards testing a specific idea or resolving a specific problem.
In this case, over and above an interest in the use of artillery, the model wished to consider general elevations of structures on Hadrian’s Wall in relation to how they were roofed.
The model is based on the plan of the Broad Wall Milecastle 48 at Poltross Burn and Turret 48A [6], with the very important proviso that the site is treated as flat rather than steeply sloping to the North as is the case at mc48.
The connecting Hadrian’s Wall and the curtain Wall are modelled in general terms without detailed consideration of the battlements and parapet, which although visually important, are less relevant to the model, representing optional detail.
Models and the diagrams they generate may be used to demonstrate a range of ideas that are contradictory or false, for this reason  Steve Oles from SketchUp, the software I used for this exercise, is included to reinforce the point that this is a form of scaled diagram used to illustrate an argument, and not an artistic representation.
Roofing
Roofing is an important design consideration in structures with wooden floors traditionally a feature of buildings, although this not always reflected in the visual culture of the Wall.
Very roughly the structure occupies about 650 m² of which about 40% is the curtain wall and towers all of which is hard surface that has to be drained.
The model wished to test, rather than a pitched roof design, the use of a simple Mono-pitched roof for the internal buildings which can be extended to articulate with the curtain wall, which in principle has a number of advantages.
  • It would drain water away from the narrow spaces between the building and the wall, where there is no evidence of a drain.
  • In an Ideal arrangement the runoff from the majority of the structure is directed towards the drains of central roadway and out through the gate.
  • Protects the steps which are built around an earth core with a retaining wall which is best kept dry for stability; 
  • Facilitates a NW Kitchen based around the oven, [baking is traditionally an indoor activity]; 
  • Covering the SW and SE corners provides a latrine and perhaps some form of loose box; 
  • Provides a complete drainage solution for the whole structure.
The key parameter is the roof pitch; 30.5° / 7:12 was chosen as the lowest practical pitch for a pitched roof with wooden shingles which could be replaced by tiles; 8:12 or 9:12 would also be considered practical.
 The remains of steps comprising four partially surviving 11” x 8” steps and a 15’ 4” retaining Wall which argues for 12’ rise on the steps; the logic of the model would be to match this with roof pitch which might suggest 8:12.  In general terms, the steeper the roof, the taller the curtain wall in this arrangement, and vice versa.  

Buildings
The basic building design has 4 separate rooms, which are shown with a central hearth, and although this is not certain for all rooms, it does imply a single storey infantry barracks.  The width of the doors also indicates there is absolutely no provision for cavalry, apart for the potential of space for loose box against the southern wall. 
There is no apparent differentiation in the design to indicate the presence of an officer, and no obvious implication to be drawn from there being 8 rooms; the century, basic component we are familiar with, is normally comprised of 10 units of 8 men. The rooms are smaller than those in typical infantry barracks; however, the latter represent the permanent residence of a unit, which may not be the case for milecastles. The precise garrison, usually put around 40-50, was presumably deemed sufficient to man the milecastle and the turrets on either side; defending the intervening stretches of Wall being impractical.
The gatehouses are shown with windows to light the internal spaces and provide additional firing positions; these a nominally based on utility and the presumed position of stairs, and doors for which there are fewer options. The roof shape chosen is a N/S oriented pitched roof, as opposed to an E/W orientation or pyramid form, the other simple contenders; while this arrangement was considered in terms of practicality, it also creates an appropriate architectural effect at the front of the structure.   
The Turret
As with the Gate house the point was to demonstrate the need for a roof given that structure would have had wooden floors and ladders or steps.
In addition to consideration of drainage, headroom required for weapons and protection from missiles is important.
In this case, a pitched or pyramid roof are the simplest options, combining the two can create more complex forms; in any event, a roof is required with a standardised form, reflecting the generally uniform nature of the structure.  Apart from the addition of a roof and artillery, this is general how these structures have been pictured.
There role has been seen as compatible with the similarly scaled small lookout and signally  timber towers evident in archaeology and art. [23]
One advantage of wooden towers is that achieving a 50’ high platform is relatively simple with the appropriate timber, which is significantly taller than the elevations envisaged for the turrets on Hadrian’s Wall.
Thus, the use of wooden super structure in addition to a basic roof, floors and fittings cannot be precluded to enhance the height, and hence effectiveness, of the turret.  However, the most significant issue encountered modelling a turret was it relationship the intervening Hadrian’s Wall.
One possibility is that a walkway was accessed from a door in the Turret, Logically, the turret would have had three doors, potentially making it more difficult to defend.
The alternative is that there is no direct access, which raises questions about the form of Wall and its relationship not only to Turrets, but also to milecastles.

Conclusions.
Not unusually, having built the model, I am unhappy with various aspects; which is precisely why models are built. 
The initial idea about that the spacing of gate towers and turrets might reflect the use of torsion bow artillery, works reasonably well, although, perhaps in keeping with the general character of the linear frontier, it would represent a minimal use of resources.The effectiveness of artillery and observation would be enhanced by height, taller the better, as is the case with most fortifications.
The issue of the relative heights of the Wall and milecastle curtain  is the principle issue highlighted, but not resolved by the model. An "Ideal" section, illustrated above, might resolve this issue and perfect the drainage.
To get this to work, the height of the wall must relate to angle of the roof and its starting height; an additional complication is the steps, which I have had to recess into the wall it give some extra height, or face issues with headroom at the top.
As this is a military structure top roof should not be higher than the wall, and it would be ideal from a drainage point of view if the wall was just higher than the roof, so that the rapid runoff from the hard surfaces of the walkway had somewhere to go. The estimated height of the wall using the 4 surviving steps puts the walkway at 12’,[6], the model is about 15’.
What is concerning about the steps is that they are not bonded with the curtain wall, while this simplifies construction, at some point it must integrate with the bonded stonework, and for the curtain to have greater height a more complex design has to be envisaged.


However, the height of the wall is problematic in other respects, in particular in how it related to Hadrian’s Wall itself. If Hadrian’s Wall and the curtain wall of milecastle are the same height, then it possible to enter via the Wall, which given how easy it would be to climb, is a very insecure arrangement that does not altogether make sense.  
For Milecastles to function as a fortification with a secure perimeter, the curtain wall has to be higher than the Wall itself, which as we have already suggested would benefit the model for roofing the buildings, if mono-pitch rather than standard pitched roof design was used.  
However you look at it, there has to be some reasonable differentiation, some method of isolating the two aspects of the frontier; since defending one mile of Wall is impractical, it makes sense to raise the milecastle / lower the Wall.

Here again we return to the essential question of how the wall was supposed to work, and whether it can be assumed to have had a walkway with battlements. If so, how was this accessed from the ground, or from milecastles and turrets?
This question is complicated by the differing phases and standards of construction evident in what remains of the Wall, where distinguishing between normal and exceptional is not always easy.

The normal arrangement seen in forts like Chesters and Rudchester is that the Wall intersects at a gate tower. At Houseteads [above] and Greatchesters, where the Fort is inserted, the junction with Wall is marked by Turrets, which in sense is ambiguous, since we have to assume that these towers are higher than the curtain wall of the fort.  In these latter forts, and Birdoswald where both cases apply, the intersection of the Wall with corner turrets at an angle makes any provision for access unlikely.   
So while the arrangement in forts makes it clear that they a physically separate from the Wall, it does not shed any light on the same relationship for milecastles as the presence of turrets obscures any inference about the relative height of the curtain wall.   
Both milecastles and turrets in their Broad Wall form were built with similar 12’ “wing walls”, a stub of wall that facilitated a junction with the linear sections of walling built by different gangs that would join them up at a later date.
To some extent this restricts the likely height of Hadrian's Wall, since this is necessary to prevent a butt joint, an offset between the successive courses of the facing [like a flight of stairs]. 
For the sake of argument; if including mortar we a looking at standard 8” course of 12” blocks [7], then a 12’ wing wall is equivalent to 24 x regular 6” offsets, which at 8” per course, suggests a height of 16’; shortening the offset / block length would increase the estimated height. It is clear that precise height of any of the elements is difficult to calculate from the existing evidence, and that the separation evident in the forts sheds no direct light on the relationship between milecastles, turrets, and the Wall.
Given the crucial role of milecastle in maintaining the integrity of the frontier, I would be inclined to the view that that they must be physically separated from the Wall in order to maintain its perimeter.  This can be achieved by a height differential, or, perhaps, by building the Wall with a top that slopes on the inside and has no walkway.   
Thus, building a model to understand roofing, one of the main approaches to Theoretical Structural Archaeology, has taken an unexpected turn, which in this case, results in a reconsideration of underlying assumptions or presumptions, which is the point of deductive reasoning, and one of the advantage of evidence based model building.
Whether, the visual culture, and the expectation it has generated, could ever conceptualise a more simplistic and less elaborate form of Wall is an interesting question, but what is more important is to be able to distinguish between what derives from artistic or textual convention, and what is rooted in archaeological evidence.

Sources and Further Reading


[1] Handbook to The Roman Wall. J. Collingwood Bruce. Published by Hindson & Andrew Reid Ltd, Newcastle upon Tyne (1966) p.26
[2] op. cit. p. 22
[3] Caius Julius Caesar "De Bello Gallico" and Other Commentaries English translation by W. A. MacDevitt, introduction by Thomas De Quincey (1915) http://www.gutenberg.org/etext/10657
[4] Aviam, M., 2007, The Archaeological illumination of Josephus; in Making History: Josephus And Historical Method, edited by Zuleika Rodgers,  pp. 354 -355,  361-2, 381.
[5] eg.  High Rochester; https://en.wikipedia.org/wiki/Bremenium
[6] Gibson, J.P. & Simpson, F.G. 1911. "The Milecastle on the Wall of Hadrian at the Poltross Burn"; Trans. CWAAS XI (New Series) Art XXIII pp390–461
[7] Handbook to The Roman Wall. J. Collingwood Bruce. Published by Hindson & Andrew Reid Ltd, Newcastle upon Tyne (1966) p.33

03 March, 2017

Systematic Irregularity; hidden in plain sight

When you start an excavation, or make an original observation, it may become your responsibility to give things a name, which is not as easy as it might seem. 
I inherited an archaeological site named Orsett “Cock”, the Cock in Question was the local pub, a perfectly reasonable and appropriate idea for archaeology in 1976, when google was just a spelling mistake.
It was working on the Orsett enclosure report, as I preferred to call it now, that I had to start naming parts of theoretical model structures, although I also floated an idea that I decided to call Systematic Irregularity.[1]
While it is my understanding that this idea exists in other forms, as an archaeologist doing detailed work on built environments, I had perceived that engineered structures were never square or rectangular, an observation that applied to both to foundations of small buildings and to layout of large ditched enclosures.
The original plans of six Little Woodbury 4 post structures [2]

14 January, 2017

Virtual Archaeology Quiz with Real Prize

What is the first thing you would teach an archaeologist?

After 150 page views with no guesses - and as a tacit acknowledgement of this venal and wicked world -  I am raising the stakes by offering a real prize to a virtual quiz.

**  The Prize  ** 

The Prize is this beautiful and valuable Corinthian oinochoe hand painted in a Wild Goat Style by a real Greek craftsman, with a genuine TPQ date of 550 bc,  it comes complete with lead seal guaranteeing its inauthenticity and Free Worldwide Postage to the lucky winner. 


The Question

What would you would  teach in lesson 1 - paragraph 1 - to your new student or employee about archaeology?
The first steps are an important moment on the path to being an archaeologist, so where would you start?

Or perhaps, what were you taught first on your first day in archaeology?  

Please feel free to confide, speculate reminisce or guess in comments below.

All answers may be marked out of 10 and the first to the correct answer will win the prize [1].


The Prize - a Corinthian oinochoe height 95 mm  [N.109] 


[1] Marked for conformity to the appropriate marking framework draw up in accordance with a subsequent clue provided or in relation the usual regulations, and in particular, those pertaining under the remit of the Sub-committee for Arbitrary Subjectivity as constituted in accordance with the accepted practices of Non-Accountability Policy Commission at the  Examinations Board of Tyneside University, produced in association with Bet-your-life Educational Services, a wholly owned subsidiary of G4S Premium Pedagogy [China] inc. of Panama [2];  Your life may be at risk if fail to choose the correct option.
[2] All apparent acronyms are entirely fabricated from existing letters, which are coincidental with publicly available and locally sourced generic alphabets, and notwithstanding any intrinsic plausibility, are works of fiction and as such are inherent deniable with no intentional resemblance to any existing, co-existing, non-existing or metaphorical abbreviations. 

01 January, 2017

2016 - Review of the Year

One of basic principles that always governed my professional practice in commercial world was “Always do what you say you are going to do”, if everyone sticks to this, then even quite complex projects can come together successfully.   Since the year started with a bold statement of intent concerning building a model of a CAD Class Ei building, some form of progress report is probably due.   However, what happens, or is reported on this blog, is a separate issue to what is going on in terms of research; you can do it or write about it; it is not that there is nothing to report, but that things are changing; you can spend weeks illustrating and writing a post about a particular problem, only to find that you have solved it. 
There are other things going on; I am virtually busy working on a range of other case studies, methodology, and projects with other people; there is even the real world, which exacts its a terrible crushing toll on a daily basis.  

03 December, 2016

Hadrian's News in Brief

Any archaeologist will tell you that dealing with press is always fun; you may get all the right words—but not necessarily in the right order, so I am reasonably happy with results of a recent press briefing to my local paper,  The Hexham Courant.  I am not sure if maverick is an upgrade on controversial, but perhaps after 7 years I've earned it, although I'll be sticking to structural archaeologist for the time being.
They had previously reported my work on the Hadrian’s Wall and I wanted to bring them up to date with my latest discovery that the idea of a “Turf Wall” –  a Roman Wall made from turfs - was scientifically unsustainable.[1] Once I had managed to get the absolute untruths edited out of the final copy, I am reasonable relaxed about the minor factual inaccuracies, and some of it is spot on.  
However, I have never learned the lesson of producing a nice crisp press release, which does most of the hard work for you, although it has prompted me to try and produce a summary of my view of the evidence for an early Wall in succinct a form, at least as it differs from traditional accounts.

04 November, 2016

Virtual Archaeology; A Roman Timber Rampart


The need to illustrate recent speaking engagements, has necessitated the revisiting a virtual model of the Roman timber rampart based on foundations found at Shields Road, Byker, which a real place in Newcastle. [1]  In addition, live reaction to my work, provides an opportunity to reconsider and improve its subsequent presentation, and thus every question, comment or observation is important. 
Since this particular technological approach, and in particular the underlying reverse engineering, has proved  too advanced for a parochial academia, it is worth restating the fundamental methodical differences between CAD modelling and visualisation of the past.  
The use of engineering  in the understanding of structures can produce models with varying degrees of certainty and spatial accuracy, but what it cannot really do is tell you what the past looked like.  While the artist’s reconstruction has become the de facto money shot of archaeotainment staples such as Time Team, and even on the front of serious archaeological reports, a picture is worth a thousand peer reviewed words, ultimately, there is no inherent entitlement or legitimacy to a visual culture of the past. 

11 October, 2016

An Irish Mystery

Over the years, all sort of interesting sites have turned up in my inbox from correspondents seeking my opinion on what they have found.  This has included a potential biblical site in the Sinai Desert that I subsequently identified as the archaeological impression a SAM missile battery, however, by far the most exciting structure arrived in the form of a resistivity survey image that I received from Ireland. 
It arrived without any detailed context information or identification; this is perfect – the biggest problem in this type of analysis is observer bias, so the less I know the better; all that matters is the data provided, in this case a survey.
Unfortunately, I get involved in this type of type of thing because I specialise in engineered structures, so like many archaeologists looking at this type of image I have a first impression.  This initial bias, which equally might also be regarded as  skill or expertise, can only be mediated by adherence to some form of deductive methodology.  Just like a police enquiry, there may be a prime suspect, but it still important to eliminate other potential suspects; if you are going to allege that this is the remains of one of largest ancient structures ever built in Ireland, you better have a watertight case.

30 September, 2016

De-turfing The Wall at Greenhead

A Date for the Diary
On Wednesday, 26th October, at 6.30pm. I have been very kindly invited by Greenhead Local History Group to give talk on the Wall as described below.

PRESS RELEASE
The Greenhead Local History Group Public Lecture in October returns!
The subject this year will be those two “other” structures that form part of the package we know as “Hadrian’s Wall : the Vallum and the Turf Wall.  We know they existed, we know roughly where they were, and can recognise bits of them as we pass by,  but few of ushave really understood much about them, and visitors often fail to notice them at all.  So we do tend to airbrush both of them from our mental picture of “The Wall” and the facts are rarely questioned.
Geoff Carter, on the other hand, has looked closely - and he has come up with some interesting questions for us to consider.  

13 July, 2016

Reading the Wall

Conference; Reading the WallNewcastle University; 15/6/16 – 17/6/16.
The Turf Wall and the Vallum: Linguistic Dislocation on Hadrian’s Wall; Geoff Carter.
Abstract;  Above and beyond the physical reality of its archaeological deposits, Hadrian’s Wall exists as a literary entity with its own distinct vocabulary including Latin loan words.   Research has often been confined to this linguistic construct, creating an understanding that has in part been conditioned by the inherent meaning of its own terminology, in certain cases this circularity has resulted in a growing discontinuity between what is discussed and what is actually present.  The paper considers this process with specific reference to the Turf Wall and the Vallum, contrasting the physical evidence in terms of their soil science to the textural narrative, reaching different conclusions as to the nature of these important early structures.
Or, in short, the paper explains that the Turf Wall could not have been made from turf, along with the more familiar idea that The Vallum was not a vallum, which has some interesting implications for our understanding of Hadrian's Wall.

26 April, 2016

Reverse engineering the past

It is spring, the swallows have returned to the farm, so it is time for a mission statement, or an explanation what after 8 years on the internet Theoretical Structural Archaeology is all about, again. 
In essence it very simple, just as knowledge of potting is necessary for understanding pottery, so understanding engineering is important for a archaeologists dealing with the archaeological remains of engineered environments.  However, this really about being able to think like potter or an engineer, it concerns archaeology as a mind-set rather than a written subject.  Not that it is actually that technical, given the sorts of the data sets we recover, and of course it is only one of many core skills required for field archaeology.  The key point to grasp, at least in principle, is that engineered structures can be described mathematically, and therefore can be modelled.  

24 February, 2016

Hadrian's Wall; understanding The Vallum

The Vallum is one of the largest earthworks in the world, part of Hadrian's Wall World Heritage site, and yet is seldom discussed, perhaps because while its interpretation may work on paper, it makes less sense on the ground.
It is an excellent example of how in archaeology, what we name something conditions the way we perceive it, and how our literary constructs  can develop independently of the underlying physical evidence. 
The Vallum is one of the oldest concepts in the literature of Hadrian’s Wall, originating with the Venerable Bede in the eighth century, and while this structure is not a vallum in any way shape or form, all subsequent literature would appear to have developed from this idea.
In more recent times, it was apparent that the earthwork was not defensive, but it was nonetheless usually regarded as a boundary or barrier between the Wall and something else, with even the language used to describe the earthwork being shaped to accommodate this underlying assumption.
However, to understand the Vallum you have to look at it with the perspective of a structural archaeologist, luckily, I see it every day, so I know with a reasonable degree of certainty that is a construction trench for an unfinished road, an argument I discussed in detail 5 years ago [here]; subsequently and more generally [here].

31 January, 2016

A blogging Carnival; Grand Challenges for Archaeology; reverse engineering Stonehenge

#blogarch
In response to the latest blog Carnival organised by Doug Rocks-Macqueen, the champion of archaeological blogging, over at Doug’sArchaeology, I am posting about the challenges of modelling a prehistoric roof structure in 3D.

The story so far…
My work is based on the idea that archaeological buildings are mathematical structures which can be detected and understood using the same principles that underpin the engineering of the built environment.
As regular readers will know, I have had the misfortune to have discovered how, in theory, the large Neolithic / EBA structures represented by postholes known as Class Ei buildings [1] worked, at least in plan and section.   The next stage is to model the structure in 3D to understand its assembly; the initial challenge is finding an appropriate starting point, since the value of everything else, and many man hours is dependent on this decision.  What is also challenging, at least in an abstract sense, is that the Ei building I am currently modelling at moment is Stonehenge, the well-known ritual monument and mystery at heart of British faith-based archaeology.

20 January, 2016

2016 A Monumental New Year

Ditched Enclosures in Neolithic Europe
I have to thank Víctor Jiménez Jáimez for raising me from the deep sepulchral gloom of my seasonal torpidity, to bring you news of his new website ; Ditched Enclosures in Neolithic Europe.
He has produced an excellent site that is not only technically accomplished, but also succeeds in conveying the physical scale and geographical spread of Neolithic enclosures. Using some of the latest information and modern methods of presentation it is an excellent introduction to the topic as a European phenomenon.  The site is completely non-profit, and is aimed at the general public, but would be a good introduction for archaeology students, as the Neolithic is a period that is best understood in a European context.

29 September, 2015

Faith, Archaeology and the Gods

Recent events in the Middle East, or rather several millennia of tragedy in the area, has highlighted the issues of Gods, and the problems they cause, so should archaeologists have any dealings with the supernatural? 
Meta-parables
Faith changes people’s lives, although it is often other folk’s beliefs, rather than our own that have the most significant impact; my life changed forever at Newcastle University where my work based on mathematics proved no match for a revelatory “Iron Age Building Cosmology”; as we shall see, when creating myth a power-base is more important than an evidence base. While rationality, at least as expressed in science and maths is universal, Gods, despite their claims are usually fairly locally based, archaeology is aware of this because we know where they lived. While Gods clearly can inhabit a variety of elements and dimensions, it probably saves confusion when interacting with human society if they have a principle residence from where they can transact their business.

19 July, 2015

Deconstructing a Stonehenge "House"

A game of blind house detective
When a reader contacted me to ask my opinion on a reconstruction that was referred to as “the Stonehenge House”, I saw an interesting opportunity for a blind test.  In truth, I had not looked at this, so I requested and received a copy of the archaeological plan from Durrington Walls on which the reconstruction was based. I fully expected to produce a different conclusion since, as an archaeologist, I try to work by deduction, rather than by comparison or projection; it's the difference between astronomy and astrology.
I sent my reply back in just over a day, in the form of the drawing reproduced below.  It was just a quick hack; it has taken a lot longer to write it up for this post, probably because in term as of scale it is more like a Stonehenge Shed, and I have more significant structures I should be working on, but being an Aries, I can’t resist a challenge.   
Regular readers will be aware that I do have serious prejudices about the nature of built environments in this period, which included  large class Ei buildings like “Durrington Walls” [1].  My interest is mainly in this main structure, which  I know was a building, even though only half survives, because I have done the maths; post-processual academics know it is “ritual” because they haven’t.

13 July, 2015

Parish Notices: An exciting new blog, a Blogging Survey with a * Prize * + the future in the Stars

An exciting new blog to visit
For some time I have been discussing some interesting research with Michael Carter of Ryerson University; He has been working on a project to utilise modern graphics engines to build virtual Native longhouses. This site gives a run-down on development of the research;
In particular the current state of the project:
This research touches on a many issues central to the use of modern computer graphics in the realisation of the past.  For my part, I am obliged by the limitation of deductive processes and reverse engineering to sidestep the issue; the intent of my practice is to understand the engineering principles behind a structure, with the classes of evidence available I cannot realistically understand its skin.  This is disappointing, because that is the vision that people think they want.   However, once you start imagining the past, there is a danger that pictures become more important than the evidence, because now they can be a lot more “real” than the archaeology.  For me the expression, recognition and understanding of doubt are significant issues.

24 May, 2015

Understanding Hadrian's Wall - why it all went wrong

What's the big idea?
It is roughly 270 years since a government in Westminster had Hadrian’s Wall systematically demolished and crushed to make the road that now brings the tourists to see the bits they missed.  It helped create a vast fragmentary jigsaw puzzle that which has proved difficult to piece together.
In 2008, I recognised that my colleagues and others had discovered, under the streets of Tyneside, the remains of a temporary timber rampart predating the stone Wall.  This observation explained the strategic methodology of Wall construction, shed light on the motivation, while providing a starting point for the process in both time and space; it was a key piece of the jigsaw; a how, why and where for the start of the Wall.

30 April, 2015

Building the Past - in Ohio

I have been blogging about the archaeology of structures for nearly 7 years, during which Google tells me I have a little over half a million page views; some of this self-selecting audience get in touch and we take things further.
One such was Bill Kennedy; we share an interest in modelling  archaeological structures from their foundations, only he builds full scale Prehistoric Native American structures at Sun Watch nr. Dayton, while I like mine to fit on my drawing board or hard disc.
So, at Bill’s instigation, we have written a chapter together in Building the Past: Prehistoric Wooden Post Architecture in the Ohio Valley–Great Lakes, recently published by University of Florida.
"This volume presents a much-needed synthesis of prehistoric wooden architecture in the greater Ohio region. The authors pursue new avenues of research in explaining architectural variation from rarely encountered Archaic domestic structures to large public buildings of Fort Ancient societies."--Cameron Lacquement, editor of Architectural Variability in the Southeast

"A significant contribution to the cultural history of the Ohio Valley and the archaeological literature on perishable architecture. The primary data and detailed descriptions of wooden post constructions make it a valuable resource."--Sissel Schroeder, University of Wisconsin-Madison