The walls of the Aran islands were perhaps the most impressive of our twelve day walking tour of walls of Britain and Ireland. The incredible variety of styles proved to me that there are more ways to wall with stone than I had ever thought.
The different styles of Feidin walls with the tall upright mother stones and the baby stones between and the taller father cope stones above were inspiring. With the myriad of structural stone patterns that were already evident, I wondered (worried?) about the concept of given infinite time and unlimited amount of stones and an infinite number of wallers (monkeys?), might there in fact not be any more walling patterns left to discover.
Painting in the lounge at the Pier Hotel on Inismore
Trying to unlock what the pattern of thinking was with each wall I inspected was like looking at an impressionistic painting too close up. Standing back you saw the order but then you couldn't figure out how it was done. The main principle seemed to be maximizing the friction between stones. This doesn't seem to mean always using hearting as the necessary binding material.
Surprisingly a stone can/may actually stay locked in place better in a wall by only having three points of contact with other stones. I think Sean Adcock has written an article about this sort of thing somewhere on his wonderfully informative StoneChat website http://www.dswa.org.uk/north-wales-g.asp. I will try to find it and do an entry on this concept later this month. His latest Spring 2010 entry is well worth a read too. http://www.dswa.org.uk/UserFiles/File/20%20Spring%202010.pdf)
The other important feature of building in the Aran style of walling was the frequent practice of locking the stones on the diagonal. This sends an energy along the wall not just down the wall. This is the same reason even the Brits lean cams and copes on their side along the top of many types of horizontally coursed walls.