Lost Technologies of Ancient Egypt: Advanced Engineering in the Temples of the Pharaohs
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Figure 9.11. The Unfinished Obelisk
It is postulated that the obelisk was abandoned because a crack had developed during the quarrying process. This seems to be a logical assumption, and it is commonly accepted to be true. Yet having invested such a huge effort in the trenching process, the ancient Egyptians—if they were continuing to create sarcophagi, statues, and other building blocks—could still use the cracked obelisk for a great deal of usable stone that was not cracked. They would merely need to cut the quarried piece into shorter sections to get some good stone for their labor. In fact, it appears that this is what was attempted in an area near the pyramid-ion, where there is a series of holes drilled in a line (see figure 9.12).
Figure 9.12. Series of drilled holes on top of Unfinished Obelisk
The line of drilled holes seems to outline a small obelisk, if you take into account that the outline also includes the groove, which may have originally been a line of holes before being dug out. Considering that the outline crosses the crack to what might be the pyramidion, it would indicate that when they were drilled the obelisk had not yet cracked. Was the crack that has long been theorized to be the reason why the obelisk was abandoned actually caused by work performed at a later date? It seems unlikely as fissures are in abundance throughout the granite bedrock, and this fissure through the granite appears to coincide with a fissure in the bedrock hill to the south (see figure 9.11).
Why the obelisk was abandoned will probably always be a mystery. There are no records that tell us that the quarry workers expended an enormous amount of resources on the granite hill and found a crack, so they picked up their tools and went to hammer somewhere else. We could speculate that all work ended while the obelisk was being excavated because of a cataclysmic event that disrupted the Egyptian civilization. All quarrying ended at Aswan and elsewhere, and it wasn’t taken up again until the Romans controlled the country in the first century BCE. In fact, the unfinished obelisk may be the last artifact to be quarried in ancient Egypt, and as such, it would represent the state of the art in quarrying and moving large objects—notwithstanding the fact that it was not moved.
As I walked around the obelisk, I noticed several areas that display evidence that has been used to lend support to the traditional theory of how the ancient Egyptians quarried granite. Egyptologists posit the simplest of methods for shaping stone. Natural materials such as dolerite are drawn from the earth with no further value added to them. The pyramidion and other parts of the obelisk have several shallow depressions that have been shaped by an object that left rounded corners at its perimeter. Nearby, a shelf of granite has the same marks, and these rounded features are commonly seen at the bottom of the deep trench that defines the shape of the obelisk. All over the quarry and in the trench around the obelisk dolerite stones were found in antiquity so it is natural to conclude that the marks left in the trench around the obelisk were created using dolerite pounders.
I walked a short distance away from the base of the obelisk to an area where granite blocks and dolerite balls were found lying around. I pondered the traditional theory while picking up one of the balls and wondered whether I was holding what amounted to a red herring and the rounded features that are seen on the surface of the granite were created by some other method? While I had always questioned this theory, after trying my hand at the methods suggested by Engelbach, my skepticism increased.
Visitors to the Unfinished Obelisk approach it from the north and follow an eastern path around the pyramidion. They can encircle it to the west, where a viewing platform is located. The retaining wall present in 1986 was removed, and the bedrock slopes down to the obelisk, where visitors can get a clear view of the trench. When I revisited in 2006, I went over to a block of granite near the platform. It looked as though someone had been there before and had been bashing at the surface. I picked up one of the dolerite balls that were lying in the vicinity and started to pound on the already bruised granite, taking note of the amount of material I was removing.
The trick to working granite using a dolerite pounding ball is to allow gravity to do most of the work. If the ball is smashed against the granite with the hands in full contact with the ball and adding weight behind the strike, severe damage to the user can occur over time due to the forces acting on the muscles and connective tissues in the arms, hands, and wrists. Those who have attempted to force the ball against the granite without releasing it have, as Lehner complained, suffered after just a short time.
The same results can be achieved without significant pain to the user if the dolerite ball is released before it hits the granite block. Nonetheless, as I went at it using this method, the results were not much better. Raising the pounder about 3 feet from the granite surface, I rapidly brought it down and released it just before it struck. I was rewarded by a puff of dust from the granite’s surface. I tried to build a rhythm and imagined getting into a hypnotic state with ancient chants timing my swing so that all thoughts of how miserable the job was could fade away and it was just me and the granite and the smack, smack, smack of the ball all day long. It was impossible. Catching the ball became very tricky; it did not always rebound off the granite along its original path. In fact, the task became quite dangerous as the ball bounced in unexpected directions. The uncertainty of the method meant my mind had to be alert. Moreover, after striking the granite successfully for about five minutes, a layer of granite dust covered the surface of the stone and had to be removed because it served as a cushion between the ball and the granite. The removal of waste from a cramped space would have been a significant consideration, as it is in all manufacturing and excavation processes. Notably, the surface finish of the granite created by the dolerite ball did not resemble the surfaces that define the obelisk.
My efforts yielded no better results than those of Lehner, Hopkins, or Tyson. Like Tyson, I was not constrained by the trench walls, nor did I have the risk of striking my toes or anyone else’s toes who happened to be next to me. Climbing into the trench, the uncertainty of success using these methods became even more obvious. There is not much room down there (see plate 18), and while anyone can crouch down and strike a ball against the bottom of the trench, the efficiency of the process would diminish significantly as the corners were worked. With a round ball, the flat horizontal surface would diminish as long as the worker was increasing the depth of the channel and not working out the corners. At some point, the corners have to be worked on, which means that the ball could not be released from the hands without bouncing off at an angle (see figure 9.13).
Theoretically, that angle is predictable, but not if the ball is egg-shaped or irregular, as was mine and as were all others that were lying around. Depending on how the ball hits the granite, it becomes quite difficult to catch and maintain a rhythm. Back at my horizontal surface, puffs of dust rose from the granite as the ball came up and fell again. After several minutes of this exercise, very little material was removed, but the nearby 13-foot-9-inch (4.19-meter) deep troughs with several test bores cut even deeper, bore stark unadorned testimony to the full scope of the work, and I questioned whether people who only knew of this inferior method of material removal would even conceive of taking on such a project.
Figure 9.13. In the obelisk groove at Aswan
Engelbach speculated that approximately one hundred thirty quarrymen worked in the trench at the same time, and each worked an area of around 26 square inches. His own experiments were unusually successful compared to the experiments of those who followed him, and he reported the following results:
To return to the trench, it is interesting to speculate on the amount of time which was expended in making it. To ascertain this, I tried pounding for an hour by hand at various times on one of the quarters of a two-foot task, and I found that I had reduced the level by about 5 millimetres (0.2 inches) average. With practice I could perhaps have done more. Let us assume that the ancients could extract 8 millimetres (3.15 inches) [sic], [should be 0.315 inches
or 8 millimeters] per hour from a similar area; then the time taken to make the trench must be the time taken to do the deepest part. In this obelisk the trench would have to be 165 inches [419.1 centimeters] to make it of square cross section and we must allow at least 40 inches [101.6 centimeters] for the under-cutting, making a total depth of trench required of 205 inches. Supposing that 3.15 inches [should be 0.315 inches] were extracted from a quarter of each party’s task per hour, it will require 4 × 205 / 3.15 × 12 × 30 or 7.2 months of twelve hours per day. The undercutting would have taken at least as long again, even though it could be done from both sides at once.9
From Engelbach’s description of his own performance, he was inside the trench when he worked. He says: “I tried pounding for an hour by hand at various times on one of the quarters of a two-foot-task.” This statement also indicates that the work was not conducted continuously for one hour, but “at various times,” which indicates that he had rested in between the various times that he pounded.
Adding together each of the various times, Engelbach pounded for a total of one hour and had reduced the level of a 12-inch (30.48-centimeter) patch by 0.2 inch (5 millimeters). Comparing Engelbach’s success with Lehner’s, Tyson’s, and my own, the amount of material he removed, if calculated properly, would be five to eight times the amount we were able to achieve. Yet there is uncertainty behind all of our efforts because no one made an accurate description of the granite before and after the work was performed. Nor were any measurements of weight taken to determine if the amount of granite removed was actually as stated.
The profile of the trench with their rounded corners shown in figure 9.13 pose a serious question as to whether Engelbach’s material removal was the same across the full surface of the 12-inch square patch and included the rise to the wall of the obelisk or the bedrock, depending on which side of the trench he performed his tests. To be confident that he had done this, we would require a more complete description of how he had arrived at his measurements. This description should include measurements from a flat horizontal plane to various points on the concave surface of the patch, including up the side of the radius to the wall, and then, after the work was performed, more measurements must be taken from the same flat horizontal plane to the same points. As it is, we have only Engelbach’s statement that he was able to reduce the level of the granite by 0.2 inch (5 millimeters).
Even if Engelbach had worked on a 12-inch square flat area and reduced the amount by 0.2 inch (5 millimeters), questions would still remain regarding the difficulties associated with dolerite balls and a horizontal-to-vertical corner radius and how they affect any conclusion we might reach in calculating the entire 13-feet-9-inch depth of the trench. As seen in figure 9.14, reducing the level of a 12-inch patch by 3 inches using a 6-inch ball would leave 11 percent more material in the corners than if the corners were squared. But this material would eventually have to be worked out by attacking the sides, or the trench would become narrower and narrower. Bringing the ball down vertically onto a horizontal flat surface of the granite provides the greatest force and, therefore, the greatest material removal. When the rounded corners must be worked, the ball has to be guided on an angle or, if applied vertically, it delivers a glancing blow. Either way, the ball will bounce off to the side and become difficult to handle. Lehner’s obelisk documentary shows the workers in the trench scraping rather than bashing the corner radius with their pounders.
Figure 9.14. Cross section of obelisk groove at Aswan
Figure 9.15. Surface area considerations using a round ball
Engelbach discusses the use of rammers, in which the dolerite is lashed to long pieces of wood and thrust like a spear against the granite. Theoretically, there may be some merit to this method, but its practical application raises the question of how much force could be applied to the wood and rope before either material failed. This becomes significant if we consider the difference between what Engelbach proposes and the information I received in an e-mail from Denys Stocks on October 31, 2001, about his experiments with dolerite pounders.
Mr. Stocks estimated that his removal rate of granite for flattening prior to chiseling a hieroglyph using a stone chisel was around 20 to 25 cubic centimeters in 45 minutes. This calculates to about 26 to 33 cubic centimeters per hour. I used this calculation in an article I had written for Atlantis Rising titled “The Obelisk Quarry Mystery,” which was republished in an anthology titled Forbidden History.10 In the article I had used Stocks’s material removal rates and calculated how long it would take to pound out a proposed workman’s patch down to the deepest level necessary to define the features of the obelisk. Following the article, I received a recommendation to access Engelbach’s book The Problem of the Obelisks. I had assumed that Stocks’s more current information would have been sufficient, but Engelbach, unknown to me at the time I wrote the article, by virtue of his exhaustive study and publication, was considered to be the authority on the obelisk-quarrying mystery.
It was also pointed out to me that Stocks’s material removal rates applied to flattening a piece of granite and were not quarrying rates. This seemed a slight quibble, for I had asked for material removal rates and did not specify quarrying or dressing/flattening granite. The limits of the tool indicated to me that whether we used the term quarrying or flattening, bringing a dolerite pounder down with full force onto granite would yield the same results. The only difference might be an occasional check with a straight edge to inspect the flatness of the surface. Certainly, from my own experience using a dolerite pounder, there wasn’t too much worry about overshooting a flat surface if an additional blow or two was taken before inspecting. Nonetheless, because Engelbach was not discussed in the article, it was considered incomplete and my calculations incorrect. Fortunately, I am now able to address that oversight.
Providing a reasonable conclusion that establishes an accurate length of time to quarry the obelisk using published information demands further field research and gathering of accurate information. For instance, the difference between Stocks’s and Engelbach’s material removal rates is so vast, it is impossible to reconcile. A fairly regular cadence for repeatedly pounding a stone ball against a hard surface would be about sixty times per minute, with the ball being lifted about 3 feet and brought down against the rock. This was about average for the beat I used in 2006. Using this beat, I could have accomplished the same flattening as Stocks—that is, flattening a small area of the granite. What is puzzling to me, though, and casts doubt on Engelbach’s results, is that his material removal rate was stated to be 464.51 cubic centimeters/hour while Lehner’s was 74.32 cubic centimeters/hour (my estimate of Lehner’s based on his statements made on the Nova documentary) and Stocks’s estimated 30 cubic centimeters/hour.
ENGELBACH’S EXPERIMENTAL RESULTS
Width of square 12 inches 30.48 centimeters
Depth of square 0.2 inch 0.5 centimeter
Hours worked 1 1
Cubic mass/hr removed 28.800 464.515
Weight of granite/cubic measure* 0.097 lb 0.0027 kg
Total weight of granite removed 2.794 lb 1.254 kg
*Weight of granite = 168 lb/cu.ft; 269 kg/cu.m
Engelbach had somehow managed to remove in an hour 6.25 times the amount of material than Lehner removed in his experiment—but he does not stop there. He speculates that the ancient Egyptians would have increased what he was able to do by 63 percent, which is ten times more than Lehner was able to accomplish.
ENGELBACH’S THEORIZED ANCIENT RESULTS
Square Width 12 inches 30.48 centimeters
Depth of Square 0.315 inch 0.8 centimeter
Hours worked 1 1
Cubic mass/hr removed* 45.360 743.224
Weight of granite/cubic measure 0.097 lb 0.0027 kg
Total weight of granite removed 4.400 lb 2.007 kg
*Weight of granite = 168 lb/cu.ft; 2691 kg/cu.m
In Stocks’s, Lehner’s, and Engelbach’s experiments listed in t
he tables above, there is uncertainty, and the difference between Engelbach’s and Stocks’s results is even more pronounced. Engelbach’s material removal rate is fifteen times greater than that of Stocks—but then he ignored his own results and credited the ancient Egyptians with removing 63 percent more material than he had removed himself in the same period of time. If we consider what might be necessary to achieve this difference, we may say that Stocks was applying fifteen times less force than Engelbach in a given period of time. This would be equivalent to four blows a minute to Engelbach’s sixty blows, or Engelbach’s nine hundred blows to Stocks’s sixty blows—which is impossible. Even the difference in the weight of the ball does not lead us to a satisfactory answer. If Engelbach’s dolerite pounders were fifteen times bigger than those used by Stocks they would exceed the width of the channel. Besides, Engelbach told us that “these balls measure from 5 to 12 inches in diameter, their weights averaging 12 pounds.”11 Could it be that Engelbach was applying fifteen times more force on the granite than Stocks? Having hefted dolerite pounders within that range, and having bashed them into granite repeatedly, I’d have to say no.