cladking Wrote:
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> These (locks) are an exceedingly simple device. A lock is far simpler than the wheel and could have been used in thousands of applications long before the
> Egyptians used them (if they used them).

1) A lock is not a simple device, it is a highly complicated movable dam used to raise or lower the ship within. There is no evidence whatever the Egyptians had locks. If you have an example that shows they did please link it.

One must master pumping of water to a different elevation also for locks to be useful. The "Screw Pump", invented by the Greeks some 1500 years after the 4th dynasty, was the worlds first useful pump. The AE used a manual bucket lift with counterweight... no way to fill a lock.

> The main problem which prohibits their use is that you can only go downhill unless you have > a water supply at the top of the hill. Of course there are hosts of other problems if
> you're trying to move very massive objects but these were not beyond the Egyptians.

There is no point in building a one-way lock system. A boat at the top of a hill would be far simpler removed and lowered on rollers than using a gated lock system.

> They were certainly capable of containing and stopping water.

They were LEARNING by the school of hard knocks. One very early dam has been shown to have blown out simply by water pressure.
They gradually learned the science of hydrolics by trial and error for the best of reasons; the Nile.

(from) [www.mnsu.edu]

""The very first Egyptian farmers waited for the natural overflow of the Nile to water their crops. However, as early as 5000 BCE they had begun to figure out ways to control the great river. In doing this, they invented the world’s first irrigation systems. They began by digging canals to direct the Nile flood water to distant fields. (One of the first official positions in the Egyptian government was that of “Canal Digger”.) Later, they constructed reservoirs to contain and save the water for use during the dry season. The first reservoir in Egypt, and the first in the world, was at Fayum, a low-lying area of the desert. During flood season the Fayum became a lake. The Egyptians built about 20 miles of dikes around Fayum. When the gates in the dikes were opened, the water flowed through canals and irrigated the fields. The tops of the dams were leveled and used as roads. During the flood season the dams were broken so that the river could pour into the canals."

One truly doubts there would be evidence of them physically breeching their dams if they had mastered waterproof gates. The gates referred to are believed to be more of a mobile barrier.

Jammer