A STONE GLOSSARY
MAY 2018
William ‘Strata’ Smith’s 1815 Geological Map, the first nationwide geological map ever published.
We are in the process of choosing the stone to be used for a new building in Cambridge. It has been an apparently exhaustive journey through marbles and limestones from the UK, Europe and beyond. We amass endless samples, and talk in detail to quarrymen, masons and engineers about bed heights, weathering, and reliability of supply, as well as the inevitable costs to quarry the stone, cut it to shape, and fix it together to form a building. One of the most fascinating elements of this process are the specialist terms used to describe building stones and their properties. Below is a list of a few favourite words, ordered to explain the material properties that have so far governed our explorations for this new project.
The Clipsham Quarry at Rutland in Lincolnshire. Clipsham Stone occurs in the Inferior Oolite of the Jurassic System, where it was laid down between 174 and 163 million years ago. Clipsham is a popular building limestone with a characteristic golden colour. We have recently worked with it at Bishop Edward King Chapel in Cuddesdon and the Sultan Nazrin Shah Centre in Oxford.
Bedding plane
Many building stones, including all limestones, are sedimentary rocks, formed by the gradual settlement and compression of underwater sediment over millions of years. The directional way in which they were formed governs their properties and how they can be used as building stones. Most UK limestones must be used ‘naturally bedded’, i.e. orientated in the building in the same way that they were formed in the ground. This means the height of the blocks is limited to the depth of the bed, rarely more than 1m in the UK. ‘Face-bedding’, when blocks are laid so their bedding planes are parallel with the vertical face of the block, can lead to rapid weathering and crumbling.
Metamorphic
A stone that began as another type of rock and changed as a result of exposure to heat and pressure over geological time. Marble was originally limestone, and is chemically identical to it. However, the metamorphic processes changed its physical properties so that it does not have bedding planes, and can be cut and orientated in any direction. This makes it ideal if tall blocks are required.
Precipitation
The chemical process by which Travertine is formed, usually when geothermally heated water is exposed to the air, causing it to degas and carbonate minerals to precipitate out from the water. Although a type of limestone, its distinctive formation means it also doesn’t have bedding planes and is workable in much longer, thinner pieces than sedimentary stones.
Oolitic
A type of limestone made from an amalgamation of individual grains called ooliths. An oolith is a tiny carbonate particle surrounded by concentric layers of calcium carbonate, which were deposited as the ooliths were rolled around on the bed of the clear shallow sea in which the stone was formed. This gives the stone an even structure so it can be cut or sculpted in any direction, a characteristic which makes oolitic stones ‘freestones’. Portland Stone is an oolitic limestone used extensively in London’s historic buildings, perhaps most famously in churches by Cristopher Wren and Nicholas Hawksmoor, including St Paul’s Cathedral and Christ Church Spitalfields.
REFLECTIONS ON IMAGES OF HERITAGE
OCTOBER 2014
A few months ago I revisited my 5th year dissertation: “The Parthenon (Elgin) Marbles; their essence and their absence”, as the possibility of writing a joint article with my MSc supervisor arose. Reading it again after so long felt like meeting an old friend; familiar and at once curiously foreign.
The much-contested issue of the Parthenon (Elgin) Marbles is well known. Since 1965 it is the subject of international political debate while by the mid ‘80s, when the first official request to the British government for their reinstitution was made, it became a national issue. The British arguments for the non-repatriation are also well documented and until now neither the British Museum nor the British Government seem particularly keen to return them.
This however had not been the burning question in mind when writing the dissertation. Having assumed that they would not be returned (and not really questioning it as right or wrong) what intrigued me was how the building, having been proclaimed a catalyst for their return, would be designed to deal with their probable absence.
Until and including 2008 the widespread rhetoric was that the spaces must remain empty in anticipation of their return so as to remind the viewer that the museum will “remain incomplete as long as the Elgin Marbles sit in the Duveen Room of the British Museum”[1]. Upon the museum’s completion however the adopted solution was to exhibit casts of the missing pieces instead, “in order to suggest to the viewer how the monument might look like when complete”[2]
Having traced the history of the display of the Parthenon Marbles in Britain and at the British Museum (ranging from the ‘cabinet of curiosities’ approach through to a more modern curatorial attitude) and the influence they had had in its architecture, I approached the subject through a ‘semiology’ lens and considered the philosophy and meaning of ‘void’ while examining architectural examples of how empty spaces, when displayed correctly, can have a powerful meaning. The resulting conclusion was that even if the Parthenon Marbles were never exhibited within the new museums’ walls, their absent presence could still be felt through a careful portrayal of their void so as not to resort to a seemingly trite and rather defeatist attitude of using a plaque or indeed casts. Evidently, the message of the void would need to be conveyed in a way as to allow an ‘open’ reading while not being so ‘open’ that it prevents us from recognising in the message a formalizable structure.[3] An empty space would then not appear as “a deficiency, a failure to fill up a cavity or gap… but a bringing – forth.”[4]
Looking back now, the discourse was interesting if slightly self-righteous. Inadvertently, the conclusion reached could read as a glorified absence that would become a pressure vehicle for their return, because it is where they belong. But do we own heritage? Heritage is thought of as underpinning our roots and the importance we bestow on the material culture “plays a vital representational role in defining national identity”[5]; as such any discourse is incredibly complex and inherently political, so much so that it becomes personal.
When I first saw an image of the façade for the athlete’s residential building within the Stratford regeneration I thought it superficial, an ornament of post colonisation, almost hubristic. Reading Niall’s ‘Peplos: The dissimulating façade’ got me thinking about this more. When the Marbles were removed from the temple they began a different journey, their identity was altered “from deep walling elements to thin relief panels” while “their dissolution, replication and dispersal”[6] made them idealistically present but always lost [7]; they don’t ‘belong’ anywhere. Maybe this facade should not be offending me but helping me to recognise the expression of appreciation for the ‘lost’ pieces of a timeless masterpiece that could almost read as a celebrated protest.
…
[1] Sands, H. (2008) “Henry Sands says Athens’ new museum is missing its Marbles” Acropolis Now [online] http://www.elginism.com/new-acropolis-museum/the-new-acropolis-museum-needs-its-marbles-to-complete-it/20080827/1289/ (Accessed 3rd March 2013)
[2] Plantzos, D. (2011) “Acropolismus”, Antiquity, no.85, p.623, [Online] http://antiquity.ac.uk/ant/085/ant0850613.htm (Accessed 9th October 2012)
[3] Caesar M. (1999) Umberto Eco: Philosophy, Semiotics and the Work of Fiction, Polity Press, Cambridge, p.65.
[4] Leach N. (1997) Rethinking Architecture: A Reader in Cultural Theory, Routledge, Taylor & Francis group, London, p.123.
[5] Smith, L. (2006) Uses of Heritage, New York, Routledge, p.48
[6] McLaughlin, N., (2012) “Peplos: The Dissimulating Façade”in Archithese.
[7] Ibid.
Pinelopi Antoniou studied at the University of Cambridge and the Edinburgh College of Art. She holds a BArch (Hons) and a Diploma in Architecture. She was nominated for the RIBA President’s Medal in 2005. She joined Niall McLaughlin Architects in 2013 and has worked on a private house in London, a private house in the Cotswolds and is currently on the Outpatients building in Oxford.