Wednesday, June 4, 2014

Day 8

Day 8

Today we toured a Bedouin museum, had a hospitality lunch, and bought some really cool woven fabrics in the Negev then hiked in the mountains near Mount Hertzel.  It was really cool, the trail was along an ancient farming terrace and there was still stuff growing like olive trees, dates, figs, berry trees, mustard seed, and the type of cactus you can eat in large quantity or turn into liquor.  We also got to go into an ancient cave that was dug out to provide water for the lower tiers of farming.  Construction was at least 1,000 years ago.  The idea was to excavate a cave deep enough into the hillside so that water seeping through the ground could get collected and funneled into a holding pool.  This was at the entrance which had a dug-in cistern.  It looked like construction techniques similar to the walls at the temple mount in Jerusalem, with stones built into the face of the cave/hillside, steps leading down into the water so you could fill up water even in the dry season, and created a retention area so large that you could stack multiple pick-up trucks in the cistern.  It wasn't allowed to walk into it today, but was very intriguing to see.  

The engineering concept here is gravity.  Each terrace was built onto the hillside by means of an ancient retention wall.  This created a stable foundation for soil to be placed behind the wall, against the hill, and leveled for farming. These tiers of walls were also built at the cave entrances where the cisterns were.  Once the pool at the mouth of the cave was filled with water, they opened a gate and drained it to the lower levels of the terrace.  It would pour onto the crops at one level and excess water would flow into irrigation channels cut into the terrace walls.  Each was about 4 inches wide.  The external irrigation had a smooth, shallow rounding to it.  The main viaduct out of the cave had a very rectangular look.  There were small slits inside of this rectangle to allow surrounding water to be funneled out of the cave.  It was an amazing feat of ancient engineering.  The terrace farming had ceased in the 1940’s, so the water doesn’t really get used today for farming, but it all still worked; as evident by our group pouring water into the channels and it flowing to lower levels. 

The best part was being able to conceptualize the whole system in relatively quick fashion with easy use of the imagination.  There were these roots coming in from the upper levels into the ceiling of the cave in search of water.  This created cracks for rain water to flow too.  The ancient engineers came into the cave and expanded it, allowing for more water to be brought into the cave.  The water flowed over these rocks and into a viaduct cut into the mouth of the cave.  This was about 3 feet wide and 5 feet tall with that rectangular channel in the center.  This poured out the mouth of the cave into a cistern built into one of the retention walls.  This created water on demand for farmers using the lower levels of the terrace.  And you instantaneously understood all of this by standing in the cave and seeing the water dripping and flowing into the channel.  

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