Friday, April 6, 2012

A safe cool place for sheep.

One of the possible reasons that these Menorcan barracas are so tall is that the more gradual corbelling of the tall vault makes it all the more structural. A lower rounded dome shape (accomplished by cantilevering stones over the opening fairly quickly) would be less stable even though it would be less time consuming to build and use less material.  
Another factor is the heat. Hot air rises and a taller ceiling would allow air inside the vault at ground level to be cooler. Crowded together under a low stone roof, sheep might still not be able to escape the extreme temperatures of the summer, unless the effect of their combined body heat was absorbed upwards by a generous expanse of large vaulted ceiling that these traditional barracas provide.

Are there perhaps other reasons why these structures are so tall?

7 comments:

  1. John, We found those internal tall vaults to be equilateral gothic in shape or close enough to make no difference. Long voussoirs laid level, not radiated, and tight to each other created the stabilty needed. The dressing on the exposed voussoir faces and the overall height of the vaults (9 Metres in one of the examples we visited) seems extraordinary just for sheep. Also the general abscense of farm workers cottages makes one think there is still much to be discovered.
    Pat

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  2. Yes. There should be some sort of record in the island's history of a massive work force (with evidence of where they were all housed) for so many of these stone towers to have been constructed.

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  3. Maybe..... The 'farm workers' cottagages were in fact the barracas you were standing in?! Maybe they were also used as Barracks during the Spanish Civil War? Maybe
    barracas meaning hut of stone were built by sheep to house people.

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  4. Is it possible that these structures had more than one story? If there was originally a second level made of wood it could explain the seemingly excessive height. Gavin.

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  5. It certainly is a mystery and there are perhaps a lot more stories than we think.

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  6. I would have thought that a tall drystone structure would have more efficiently shed water away from the internal parts and the sheep inside than say a low one. I am only a beginning waller but it stands to reason that perhaps a drystone structure being porous if it was high the extra stonework would give more time and opportunity for the moisture to shed outwards in a storm etc. A flatter corbalded structure would not hold up the rain and perhaps moisture would run straight through the stonework. It would be interesting to be in one in a storm and observe how much water comes through the roof
    Yous
    S R Briggs

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    Replies
    1. Also by having a nneatly dressed interior the water would run down the internal walls whereas if there was irregular iterna blocks the water would drip off and onto the sheep etc inside.

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