New takes on dry stone walls

Dry stone wall in England

A musician acquaintance has written some music and painted scenes to celebrate a very long (22 miles) dry stone wall in northern England. I never thought of walls and music together, but these are exceptionally poignant. "Wall to Wall" is the name of an exhibition of music and paintings by Martin Matthews. On his website, the paintings are accompanied by a couple of music tracks by himself playing northern-style tunes on the banjo that can be run while gazing at the picture. What a delight!

Dry stone walls are a feature of the English countryside. Once they are built, they tend to stay put forever for two reasons. Because dry stone walls are a product of clearing rocky ground that cannot be farmed, they tend to enclose pasture for sheep. Unlike fertile crop fields surrounded by hedgerows, stone walls are not destroyed to enlarge the fields; hundreds of miles of hedgerows have been lost to such "efficiency" enlargements.

Secondly, it takes a long process of natural invasion by plant life to deconstruct a well built wall; and then one is left with a pile of rocks in the landscape instead. It is sobering to think that most of the 250,000 miles of dry stone walls in Britain are at least 200 years old, and some date back to the Neolithic, 5500 years ago.

So now you've read this far thinking, "what is a dry stone wall?". A very complicated structure indeed that takes knowledge to build and to maintain. The Guardian ran an article on dry stone walling where an expert explains exactly how to build one. It is one of the traditional crafts of the countryside, along with roof thatching, hedge laying, blacksmithing, stonemasonry – what The Guardian calls "disappearing acts". The video accompanying the article has drawn a number of interesting comments. You can learn a lot from these resources and even find out how to attend courses and become a dry waller.

In closing, take a look at this new version of a dry stone wall. Now, if this isn't ingenious, I don't know what is!

New-style dry stone wall for a bike shed in Cambridge

Paris CDG Terminal 2E architecture

It seems to be a obsession. I am documenting the new airports of the world...

Here is the 2E K-gates terminal building at Charles de Gaulle Airport in Paris. Another beautiful use of wood in the interior, like Madrid. Moreover, the terminal floor is encapsulated in the oval tunnel, which wraps itself around the floor as it extends to the lower jetway. Really beautiful, innovative architecture – though now a few years old. The wooden ceiling of the boxy security area is frayed and not so attractive.

It is unclear which part of terminal 2E collapsed in 2004, but if the K-gates departure area is new, it dates to 2008, otherwise 2003. There is a nice YouTube offering of the 2E E-gates which look substantially like the K-gates area (I have never experienced such a confusing nomenclature of terminals and gates as at CDG).

To the left is the roof over the jetty, and below you can see how it curves around down under the jetty to meet the ramp to the jetway.

Despite the collapse, the building maintains its curved structure without any internal supports. Apparently it wasn't the architectural design that was at fault but material defects, which I hope have been corrected. A shame if it is rebuilt in a boxy style, like the Kansai International Airport (KIX). Soaring spaces, yes, but all rectangles, steel and glass. No soft woods, soft lines that really sooth when travelling.

I am the Vindo Viper

Did you ever play the telephone game when you were a kid, calling up someone unknown and saying (in your deepest bass voice): “I am the Vindo Viper. I come for you today.” Of course, the recipient is terrified and immediately hangs up. You call them again, and repeat your message, but then they hang up before you finish. Finally, you call again, saying “I come to vipe your vindos. I come today.”  Ha, ha, laughs all around.

No? Maybe it was just an American thing because we all had telephones in those days.* It certainly wouldn't be politically correct today.

But this scene on the CityPoint entrance, near Moorgate tube station, brought back those telephone memories. How many window wipers can you see? I count four. Just think what great transferrable skills these guys got mountain climbing, since they all seem to be on belay. The eight Singaporean house cleaners who recently died could have used some of these skills. They were forced to wash the outside of windows in skyscraper flats; I wouldn't like to fall off a building, would you? Apparently the Singapore government is reviewing the situation... 

CityPoint skyscraper entrance near Moorgate tube station, London

CityPoint, formerly the Britannic House, has enough accolades for listing in Skyscraper News. I guess this is a website for building spotters, kinda like train spotters except the spotters themselves have to move around to see fixed sites rather than stand still watching moving trains.


* Unlike in Britain, where only 35% of households had telephones even in 1970 (according to the only stats I could find) [http://www.bbc.co.uk/news/magazine-12058944]

Durham's venerable 'vennels'

What's a vennel, you might ask. Wikipedia defines it as a 'passageway' and explicitly says they are common to Scotland and Durham! Well, Durham was once contested land between England and Scotland, so it is no surprise that customs should be intertwined.

As the far northern outpost of the Norman conquest, Durham Castle was built by the command of William the Conquerer in 1072 on the peninsula formed by the River Wear (pronounced 'weir'). The castle was followed by the building of Durham Cathedral from 1093. Castle walls surrounded the castle and cathedral to the south, but those on the east have disappeared and been replaced by buildings in medieval times.

A covered vennel leading to Vennel's Cafe,
off Saddler Street in Durham

Vennels are narrow passageways that wind between the buildings crowded so close to the castle grounds. One vennel opens onto an inner courtyard, used as a patio for none other than Vennel's Cafe; another vennel leads out of the courtyard in another direction. Both of these vennels (but not the patio) are covered, as they form tunnels; but other passageways are open to the sky, notably Moatside Lane.

Vennel's Cafe is a very popular locus for lunch and tea – great sandwiches and cakes. I particularly like the brie and grapes sandwich, while their banoffee pie is to die for...

Moatside Lane, an open air vennel,
taking off opposite the Post Office
on Silver Street, Durham

Such vennels are great fun to follow, especially since on first try, you don't know where they lead. Moatside Lane in fact takes you up onto the western cliff of the castle, running just under the castle wall. From there you can reach the Archaeology Museum, Palace Green and the Almshouses coffee shop.

Plutonic lunch: new understandings of Shap granite

Recently, we ate lunch at the Honest Lawyer pub outside Durham – an oxymoron for sure. Staring at me from the table was the belly of a possible volcano: a granite tabletop! It looked suspiciously like Shap granite from Cumbria, but unfortunately the quarry provenience was not known to the waitress.

As any volcanologist (but who else?) knows, granite is mainly formed in volcanic arcs where magma rises through the Earth's crust in 'diapirs';  most of these diapirs solidify as plutons 5 to 20km deep in the crust, but some make it to the surface where magma is extruded through volcanoes as lava or volcanic ash. The magma that doesn't make it out cools slowly in the chamber or pluton, allowing very large mineral crystals to grow. In this kind of pink granite, the large pink rectangular crystals are potassium (K-)feldspar, also known as orthoclase. Regular feldspar (plagioclase) forms the white crystals surrounding the large pink ones, while the grey bubble-like crystals are quartz, and the black grains may be biotite or amphibole.

Shap granite is featured as the Rock of the Month for December 2011 by the Open University. The Shap granite outcrop in the Lake District is intrusive into the Borrowdale Volcanic Group, which was once an island arc off the micro-continent of Avalonia in the Iapetus Ocean between 460 and 444 million years ago [1]. However, Shap dates later via processes quite different from the subduction zone granite emplacement described above. After Avalonia was accreted to Laurentia (North America), the area of the Iapetus suture in northern England (demarcated by the Solway tectonic line) was subject to magmatism on both north and south sides of the suture. It is thought that a period extensional tectonics, creating a pull-apart basin 21km wide, was able to generate higher temperatures that caused both mantle and crustal melts to rise into the upper crust [2]. These were emplaced in the subsequent period of Acadian Deformation between 400 and 390 million years ago. Shap granite, therefore, stands as the representative of a newly understood source of magma generation that is totally divorced from subduction tectonics.

Many buildings around England feature Shap granite floors or columns. So you can also walk on it  or bump into it as well as eat off it. Just keep those sharp eyes open for Shap and you will be rewarded by a trip to the center of the Earth (or at least 5 kilometers down where granite forms).

Oh yes, and the Honest Lawyer has great Eggs Benedict. Did I say lunch? Maybe it was brunch...

[1] Huff, WD; Bergström, & Kolata, DR (2010) "Ordovician explosive volcanism," pp. 13-28 in The Ordovician Earth System, ed. by FC Finney & WBM Berry. Geological Society of America Special Paper 466.

[2] Brown, PE; Ryan, PD; Soper, NJ & Woodcock, NH (2008) "The newer granite problem revisited: a trans-tensional origin for the early Devonian trans-suture suite". Geological Magazine 145.2:235-256.

English Houses: pebble dash & crazy paved surround

And here's something we couldn't understand at first. The house we bought in Cambridge so many years ago was described in the Estate Agent (Realtor) leaflet as having pebble dash front and a garden pool with a crazy paved surround (what?). 'Surround' isn't a noun in American English; of course, it comes from the verb 'to surround' and it means something around something else. Then, 'crazy paved' isn't a verb in American English; but of course it means being paved crazily.

Crazy paving and its disadvantages

It still wasn't clear what the crazy paved surround was all about until we went to see the house. There in the back garden (not yard)* was a small pond with a concrete-tiled area around it, much like in this photo. The fact that the tile pieces were not of regular size and shape made it 'crazy'.

The other day, someone was trying to find our current house and asked me on the phone, "Is it the one with pebble dash on the side?". I had to stop and think, because I don't usually consider this house having pebble dash. But indeed, the whole west side of the house is pebble dashed!

As in the photo, you can see that pebbles are embedded into concrete. I was amazed to see this being done once while renovating, the builder having a bucket of pebbles and throwing them by the handful at the wet concrete. Some fell off and we had to clean up later. And much later, more fall off, as you can see from the empty pockets here.

Pebbledash on a house in England

Pebble dash is characteristic of inter-war houses, built between the Great War (World War I) and the Second World War (World War II) or soon thereafter. It isn't much used now: must be the labour costs are too high, to have someone standing there throwing pebbles at the house.

Just for comparison, here is an American 'crazy paving' – stencilled on at Trimble Hot Springs!

Crazy paved stencil in America

* A 'yard' in England is a paved area, like a courtyard; and 'garden', as I've said previously, means 'lawn + flowers'.

Cambridge Building Spree

Anyone who has lived in Cambridge, moved away, and then returns for a visit will be astounded what is going on south and west of the station. It is common knowledge that when the rail station was built, the colleges conspired to have it sited as far out of town as possible, out by the cattle market, the lumber yards and grain elevator.  This was to keep the students from quickly jumping on a train to London.

A bicycle bridge erected in the early 1990s opened up the area south of the tracks to new housing, and blocks of flats now line the railway. The cattle market was ended and turned into a leisure centre, marked by a parking garage and a dance venue. This was matched by downtown development of a new shopping center dwarfing Lion Yard.

But here we are in the 2010s and all sorts of construction is going on along Hills Road south of the station turnoff. At the head of Station Road, for example, a 7-storey building is being erected, completely out of character with the surrounding buildings and vying with the Catholic church steeple in height. Continuing south, one comes to a whole neighbourhood of new blocks of flats on the left in the Cambridge Gateway project, some completed, some just going up. Then at the junction with Cherry Hinton Road, the street going west is loaded with apartment blocks, while the old cattle market on the left has acquired a Travelodge, a multiplex cinema, a bowling alley, and a row of shops including the ubiquitous Tesco. Cambridge is growing southwards, with gusto!

Cambridge Gateway project with the old grain elevator in the distance;
looking east towards the station from Hills Road

The old cattle market, looking northeast from Cherry Hinton Road

Looking west from the head of Cherry Hinton Road