Seven of us set off to the south part of the island Saturday morning to study the walls closer and do some experimental wall building. Our heads were trying to get around the thought process that goes into building unusual walls like the ones that we were seeing all over the island. Certainly the shapes and sizes of much of the stones were not much different than types of random stone piles I've seen in parts of Canada.
The material is a unique limestone, and though it is very dense (170 pounds to the cubic foot) and very abrasive (giving it an incredibly gritty surface) it still wasn't enough to explain why the stones could be put into arrangements that are not very often seen anywhere in Britain or Canada. It separates in distinct chunks from the coastal bedrock landscape called karst http://members.shaw.ca/karst.almighty. The crack lines are called clints and the smooth surface spaces are called grykes.
The first thing we realized was that building on very little soil, and in many cases right on a bedrock foundation was likely to make a lot of difference in the options you had in the way you might build livestock partitions. The types of tall walled, small parceled agriculture enclosures found on the Aran Islands were devised to accommodate the forming of soil over time which was much needed for growing pasture crop and garden produce.
As we started to build our experimental wall from the broken down material of an old wall that we were given permission to work on, I remembered some of the things I had written down in my notebook that Patrick had been talking about over the last few days.