...And the Walls Came Tumbling Down

    The last two days, I've had occasion to investigate the city of Jericho, and the development of technology during the Upper Middle Ages.
    The city of Jericho was founded 10,000 years ago, in 8,000 B. C. Jericho must originally have been built of sun-baked clay, perhaps using bricks. Bricks are standardized units, like Legos, that can be used to construct edifices of almost any desired size and shape. Jericho is probably a cut above the cliff-dwellings of the Navajos or the Pueblos, and more like Macchu Pichu and Teotihuacan.
    Jericho lies "in a land of milk and honey", about 7 kilometers west of the River Jordan and about 10 kilometers north of the Dead Sea. In other words, it's within easy walking distance of either one of them. Both bodies of water would have lent themselves to water-borne commerce. Jericho is nourished with clear mountain water emanating from abundant four-season springs. One of them, Ein Al-Sultan, puts forth about 190 liters (52 gallons) of water a second.  This clear mountain water is used for both drinking and irrigation. (In two months time, this rate of flow could fill a lake one kilometer on a side by one meter deep... enough to provide major irrigation.) Jericho is famous for its citrus fruits, dates, bananas, flowers, and winter vegetables. 

Below: The Monastery at Wadi Kelt                            Below: The Oasis at Wadi Kelt

The Excavations of Old Jericho
The Dead Sea

   Jericho is the world's lowest city, lying 250 feet below sea level. The climate is dry but equable, with temperatures ranging between freezing and about 86 degrees F (30.5 degrees C). Jericho lies at the foot of the Hill Country of Judah, with mountains rising more than a kilometer above the city. Across the valley of the Jordan, lie the mountains of Moab (Mount Nebo, where Moses is buried). The area has mean annual rainfall of about 60 inches.
    What is so striking about this is that 8,000 B. C. is close to the beginning of the Neolithic Age. Metals were unknown in 8,000 B. C. other than for copper bracelets and necklaces. Everything would have been made of wood, bone, stone, horn, or baked clay. Fired pottery and cloth would have existed, but building a wall, together with watch towers and gates, would have been a back-wrenching undertaking. However, Jericho would have been on a main trade route and in a valley ideally suited for settlement. The Dead Sea could have been plied with log rafts or dugout (burned-out) log canoes. The living would have been relatively easy, which would have allowed time for activities besides subsistence.


Technology in the Middle Ages

      We're accustomed to think of the Middle Ages as technologically stagnant, but it was anything but. Technological advancement seems to have been an omnipresent feature in Western Europe. One of the earliest European inventions was the stirrup, which revolutionized warfare by shifting military superiority from infantry to cavalry.
    The development of the harness for horses and oxen cushioned the load they pulled and allowed them to pull twice as hard as before.
    The Romans had occasionally used water wheels and even mills, but the Europeans brought this to a higher art, damming the streams of Europe.
    Anr important agricultural development, attributed to Charlemagne, was the institution of the three-crop rotation scheme. Prior to 800 A. D., peasants would leave half their fields fallow and would plant the other half. The three-crop rotation scheme, left one-third of the fields fallow, planted another third in leguminous crops such as peas or beans, and then planted the remaining third with conventional crops. Not only did this increase the usable land from one-half to two-thirds but in addition, the legumes fertilized the soil, rendering the land more productive. This innovation translated directly into a higher population density.
    Another crucial innovation was the heavy moldboard plow, appearing around 1000 A. D. The heavy plow was able to turn the dense ground of northern Europe, opening new land to cultivation.

 The 12th century saw the invention of a loom with foot pedals which enabled weavers to create cloth more quickly and inexpensively. Conventional weavers opposed the new loom, which they recognized as a threat to their labor market. The subsequent invention of the spinning wheel, which made thread faster than before, led to skyrocketing in the production of cloth. The speed of production led to increased popularity of linen. Sheep farmers rioted because the cloth that was being made was not wool.
    Wool has had a hot-and-cold reputation among the public. In ancient Mesopotamia, and Egypt, linen was the cloth worn by kings and priests, with wool the low-prestige fabric for commoners. 
    Paper was introduced into Europe from Moorish Spain around 1250. Italy became the major European paper-producing country. This occurred at the beginning of the Renaissance, when Genghis Khan's conquest of China and of Islam opened the floodgates to East-West trade. (This was the century when Marco Polo visited Cathay, and brought East and West together.
    The linen cloth wore out quickly, but was so cheap that people simply threw it away as casually as we do paper towels. Piles of discarded linen were used to make rag paper, in turn causing the price of paper to drop precipitously. More riots ensued, again by the sheep farmers, because linen paper supplanted sheepskin parchment. Increased availability of paper led to increased demand for scribes, especially in the wake of the radical population reduction during the Black Death. Scribes went on strike for higher wages, driving up costs. In 1450, Johann Gutenberg eliminated the debate by creating the printing press, which the Church fought because it would encourage free thinking.
    Michael Crichton, in "Timeline", has the 14th-century French water-wheel at Castelgard driving a set of "robotic" hammers for working iron.