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1. Resting on a sled that moved over rollers, the giant obelisk was pulled to the edge of a steep ramp.
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First Attempt
by Rob Meyer
In 1995, a NOVA team dared to demonstrate firsthand what has mystified
historians for millennia: how to raise an obelisk using only materials and
techniques the ancient Egyptians might have used. Archaeologist Mark Lehner
relied on scholarship to investigate these materials and techniques. Roger
Hopkins, an expert stonemason, pushed the group forward with an unyielding
optimism and a keen knowledge of the granite that they were to work with. The
late Aly el Gasab, one of Egypt's foremost specialists in moving
heavy statues, brought his vast experience to the project and motivated the
hundreds of Egyptian workers who struggled to accomplish this monumental task.
Finally, Martin Isler, a sculptor and graphic artist with a passion for
stonework, provided his own theories and tried to keep the team's ideas
realistic.
2. Once the obelisk began to pivot over the edge,
three braking ropes attached to the monument's tip were pulled taut to control the fall. Were the ropes to fail, the granite obelisk would violently smash against the ground and crack.
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The first challenge was to secure an obelisk, which the ancients traditionally
sculpted from a single piece of granite carved from quarries in Aswan. Lehner
sought hints about ancient quarrying at the so-called Unfinished Obelisk, a
monolith that some unidentified pharaoh abandoned after structurally dangerous
cracks appeared during its removal. Other evidence suggests that ancient
laborers pounded away the surrounding granite with round hammers of dolorite,
which is harder than granite. Foremen likely assigned small "working patches"
to each laborer, who would spend months or possibly even years chipping away at
the hard granite. It was not long before Roger Hopkins, the stonemason,
realized that, if the team wanted an obelisk anytime soon, it needed a
shortcut. The crew then brought in bulldozers and other modern machinery, which
quickly quarried a large obelisk for the NOVA team.
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3. Once in place, the obelisk was removed from its sled and gently fell right into the turning groove.
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Before trying to raise the new obelisk, the team explored a number of issues
surrounding these sculptural wonders. How did the ancients transport them from
the quarries at Aswan to Thebes and other New Kingdom capitals farther down the
Nile? The polished sides and beautifully carved hieroglyphs of existing
obelisks were examined for clues. Using model boats, team members traded
theories on how the pharaohs' engineers placed these gargantuan monuments,
which could weigh up to 440 tons, onto boats and shipped them down the Nile.
Finally, Martin Isler lead the team in successfully raising a smaller, two-ton
obelisk using a levering technique.
4. Pushing down on a lever placed under the obelisk and pulling
on a rope fixed to its tip proved futile. Once the angle became too steep, the lever became too high for the men to
effectively use it. The pulling rope only pushed the obelisk down into the turning groove.
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After some delay, the large obelisk was ready for raising. Tensions mounted as
each member of the team advanced his own theory as to how to raise it. Isler
felt levering alone could do the trick. Another proposed technique called for a
giant counterweight, attached to the bottom of the obelisk, that would swing
the shaft up like a seesaw. Hopkins was convinced the answer lay in building a
great earthen ramp up to a specially designed chamber containing sand. In this
scenario, laborers would carefully tip the base of the obelisk into the top of
the chamber, then begin removing sand from a trap door in the chamber's base.
When the obelisk reached a pedestal at the bottom of the chamber, team members
would ease one edge of its base into a so-called "turning groove," which would
hold the obelisk in position as other laborers pulled it upright.
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Aly el Gasab
skillfully directed the Egyptian crew that carefully lowered the pillar down
the ramp and into the turning groove.
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The team agreed to adopt the ramp technique but decided that sand was not
dependable. Instead, it was the vision of Aly el Gasab that drove the final
stage. First, the crew put the obelisk on a sled and hauled it on rollers up
the ramp. Once it began to pivot over the top edge of the ramp, workers yanking
down on ropes fixed to its top controlled its descent down another, steeper
ramp into the turning groove.
So far so good. The obelisk then rested at a 32-degree angle from the ground.
Workers with levers quickly forced it up to about 40 degrees—nearly
halfway to success. Once at this angle, however, the team proved unable to
get the leverage necessary to raise the obelisk the rest of the way. Workers
redoubled their efforts, pulling hard at ropes fixed to the obelisk's tip. But
this simply forced the shaft's butt end deeper into the turning groove. As the
sun passed the horizon, they realized with a shudder that they had but one more
day.
Roger Hopkins ran the pulling rope over an A-frame to give the pullers a
mechanical advantage.
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Early the next morning, Hopkins set up a large A-frame, over which he ran the
rope tied to the tip of the obelisk. By adjusting the angle of the rope in this
way, he hoped to give the pullers a mechanical advantage: Now they were
essentially pulling up rather than down. Alas, this last-ditch effort proved
futile. The ropes on the pullers' side of the A-frame angled down too steeply
for enough workers to reach them. Another ramp was needed—one whose angle
matched that of the rope—but time had run out.
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5. In an eleventh-hour effort, the rope was run over an A-frame in order to give more lift to its pull. Unfortunately, this resulted in the rope being too high for the pullers to reach, and the obelisk never was raised beyond 42 degrees.
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While unsuccessful in meeting their goal, the team members had learned much
from their efforts—knowledge that they will apply during their second
chance to raise an obelisk.
Rob Meyer is Production Assistant of NOVA Online.
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