11 - Djedforce
Original version February 2009.
Completely reworked October 2019.
That the ancient Egyptians had knowledge of hydraulics can be demonstrated by means of some wall reliefs in stone that can be found in a narrow underground crypt in the temple complex of Dendera, Egypt. It was the sanctuary of Hathor and also of Isis.
Picture taken by Rowan - see Wikimedia Commons.
Figure 1: The vast majority of these images can be found as part of the "Dendera Light" theory. According to the latter, the figure above would represent a huge light bulb and the snake inside would be the filament. The above picture is the only one where the hands touch the filament and therefore the only one that allows to form a closed circuit that makes a current through the filament possible.
If you absolutely adhere to the theory of the electric light bulb, then the following topic is nothing for you. In that case, the only thing that can be said here is: "Let The Light Shine Upon You".
What is there to see on figure 1? An enormous amount of water, depicted as a very large water bubble, flows from a water hose which seems to be connected to a sort of column. There sits a snake in the middle of that water bubble, the hissing sound that a snake makes stands here as symbol for water under (high) pressure. If water escapes under pressure from a water hose or pipe this makes a sound that is indeed comparable to the hissing of a snake.
Equally important, if not more important, is the presence of a Djed. The Djed pillar is depicted with two arms and hands. It is a symbolic expression that makes it clear that this Djed is performing or undergoing an action. As the hands are drawn above, they want to make it clear that the Djed receives the pressure from the water, is put under pressure. There are also other reliefs to see (Fig. 2) where the Djed seems to push the water away.
Picture taken by Olaf Tausch - see Wikimedia Commons.
Figure 2: The light theory cannot be applied to the above image because the hands do not touch the snake (the filament) and therefore no closed circuit can be formed that directs current through that filament. It is therefore not about light bulbs here, but rather a symbolic representation of hydraulic systems. It’s an explanation of hydraulics represented in the form of a rebus.
The Djed Pillar.
A Djed (pillar), originally a piston as part of a hydraulic cylinder?
Originally a Djed (pillar) was nothing more than a tool, a part of a hydraulic system. It was a piston that belonged in a closed tube which together formed a hydraulic cylinder.
Later, much later, the Djed as well as other "tools" have acquired a religious meaning, the original purpose or use thereof has been lost. It should become clear that there has been a group of individuals in ancient Egypt who had a much higher degree of intelligence than the rest of the population. But apparently they have kept that higher knowledge for the greatest part to themselves. Why exactly this science was lost or not has been passed on to later generations is a mystery.
The hydraulic fluid used today is a type of oil that cannot be compressed and does not affect the pipes and seals. Water also has very good hydraulic properties, but has the disadvantage that it can freeze. In ancient Egypt people would certainly not have been bothered by that, so water was used at that time.
Very important is the fact that water for use in hydraulic systems must absolutely be free of air because air bubbles can be compressed very easily and would completely destroy the proper functioning of a hydraulic cylinder. Cf. air in the brake lines of your car = no more brakes!
It was the task of the Osirion to supply water under (high) pressure that had been purified and stripped of all air bubbles.
See the resemblance to contempory pistons.
Nowadays pistons in the cylinders are sealed airtight with metal sealing rings.
A Djed pillar as a piston in a hydraulic cylinder.
It has remained unclear for a long time how these pistons were sealed in the cylinders at the time of ancient Egypt. The proponents of the electric Dendera light bulb have provided the answer themselves. Apparently, several Djed pillars have been found in the past around which copper wire was still present, for them clear evidence that the Djed was an insulator.
For the power supply of the Dendera lamp, reference is often made to the "Baghdad battery". Similar cells generate approximately 1 Volt and can only provide little or virtually no current. If such, sometimes large Djed Pillars with all those rings, were actually electrical insulators they could be used to isolate voltages of as much as 10,000 to even 100,000 volts. For voltages of up to 100 volts and even more (100 and more such batteries in series), such large insulators as Djed pillars were absolutely unnecessary, a thin layer of linen covered in resin or bitumen would have been more than sufficient to insulate the copper wires. This should make it very clear that a Djed was certainly not an electrical insulator.
Anyhow, wires of soft red copper may have been used as a good sealing material between the Djed and the inner wall of the hydraulic cylinder.
It is very striking that Djed pillars are often shown in pairs and often together with the Tyet symbol.
The Tyet symbol or amulet.
The shell in the image of a Tyet makes it clear that this symbol must have something to do with water. It may well be that this was originally a kind of tool or device whose use and meaning has been totally lost and much later has again acquired a religious meaning.
There is some similarity to our contemporary fire hydrants.
Was a Tyet originally a branch point for water under (high) pressure or was this the symbol for a water tower?
The Djed pillar and the Tyet are apparently inseparably linked.
Purely theoretical representation of a hydraulic cylinder with a Djed pillar as a piston.
A possible application of a hydraulic cylinder to lift heavy stones.
In volume 2 of his Histories, Herodotos  describes the great pyramids quite extensively, and also noted what he was told about how the pyramid of Cheops was built. In this context, however, he only deals with the way in which the large blocks of limestone were transported to the higher floors, his description of the hoists used at the time still poses serious questions for scientists.
125. This pyramid was made like a stairway with tiers, or steps. When this, its first form, was completed the workmen used levers made of short wooden logs to raise the rest of the stones. They heaved up the blocks from the ground on to the first tier of steps. When the stone had been so raised it was set on another lever that stood on the first tier and a lever again drew it up from this tier to the next. It may be that there was a new lever on each tier of the steps, or perhaps there was but one lever that easily lifted, which they carried up to each tier in turn, when they had taken out the stone. I leave this uncertain, both ways being told me.
Translation of a Dutch more recent version:
[Herodotos 2-125] “I will now explain how the construction of the pyramid proceeded. This happened in stages. Some speak of tilting, others of terraces. They started with the base and then the other blocks were placed on the first layer with the help of small hoists made of short beams. If a stone had landed on the first platform, it was then taken to the next by another device and so on, higher and higher and higher. There were just as many cranes as terraces. Another possibility was to use no more than one hoist that, because it was easy to move, they lifted from low to low as soon as the load was unloaded at the designated location. These methods are both mentioned and so I have to mention them. "
In the book  the following footnote was added: “This caput is one of the most difficult in the entire book. According to modern explanations, Herodotos is guilty of anachronism here. The hoists he writes about only became known at the end of the sixth century BC in Greece '.
From Wikipedia, the free encyclopaedia see:
Herodotos (born around 485 BC - died between 425 and 420 BC) visited Egypt twice, perhaps between 460 and 444 BC. He wrote his History about 430 BC. Greek cranes were only invented at the end of the 6th century BC. (ca. 500 BC). Herodotos may have seen these cranes in operation, but at the time of the pyramid building (around 2550 BC) they did not yet exist. It is equally possible that the texts of Herodotos were not related until much later to cranes that existed in his time and that translations and interpretations were increasingly based on those lifting devices of Greek antiquity.
Really? Wouldn’t it be possible that Herodotos indeed has heard a description of "hoists" that were used by the workmen in ancient Egypt to build the pyramids? This without, however, understanding the operation of possible hydraulic “lifts”. Those short posts may well have been hydraulic cylinders that were made, for example, from a hard type of stone or even from hardwood. Why not?
A purely theoretical model of a hydraulic "lift" (4 Cylinders).
In the above case, a hydraulic "lift" with 4 cylinders (short beams).
This could also have been possible with two hydraulic cylinders.
According to Herodotos there was one "hoist" per floor level of the pyramid. Perhaps these were indeed light, relatively easily movable hydraulic hoists.
According Herodotos, the stones were lifted from one floor to the next one.
There was such a device on every terrace or battlement.
Did they do it with the use hydraulic hoists?
References to chapter 11.
 - Herodotos – Het verslag van mijn onderzoek.
Uitgeverij SUN – 2é druk 1995 – ISBN 90 6168 442 0
Boekdeel 2 – 125 vanaf pagina 185.