The Great Pyramids
Located on the west bank of the Nile River on the outskirts
of Cairo, the pyramids at Giza, Egypt, rank as some of the best-known
monuments in the world. The ancient Egyptians constructed the pyramids to
serve as royal tombs. Built without the use of cranes, pulleys, or lifting
tackle, the massive structures stand as testaments to the engineering skills
of their makers.
More About Pyramids : Introduction : What is Pyramid : How to built Pyramid : History : Khufu Pyramid : Photo Gallery
Monolithic, smooth sided pyramids did not just suddenly appear in Egypt. There was an evolutionary period, leading to the great pyramids of Giza that began with simple mastaba tombs, expanded into step pyramids, which led to experimentation, some of which failed miserably, and culminating with the perfected structure. In addition, the decorative themes associated with pyramids also evolved over time.The ancient Egyptians loved pyramids. There are sixty-seven, of various sizes, scattered around the city of Cairo alone. The most famous, and largest, are at Gizeh, where what is believed to be the three tombs of Khufu, Khafre, and Menkure, are lined up side by side.
The end tomb, Khufu's, which is often referred to as "The Great Pyramid"just by itself is an impressive structure. It stood 480 feet tall when completed and contains twice as much volume as the Empire State Building. Until the 19th century it was the tallest building ever erected. Not bad for a structure 45 centuries old.
So, how did the ancient Egyptians construct such an impressive monument so long ago? Some wild theories exist. Swiss Author Erick von Daniken suggested that aliens assisted the construction using advanced technology. Herodotus of Halicarnassus, a Greek writer who viewed the pyramids around 450 B.C. was told that giant machines were used to lift the blocks into place with the aid of 100,000 slaves working, for the entire year, for twenty years.
Probably neither of these are correct. Most likely the Pharaoh employed a large work force, indeed as many as 100,000 men, but for only a fraction of the year. During the months of July, August, September and October, the Nile River flooded the land. This was actually a blessing for the Egyptian farmers as it allowed new fertile soil to be laid down over the fields. But it meant the farmers were unable to grow crops during this period. It is likely that the Pharaoh required his subjects to work on public projects, like the pyramids, during this season.
Egyptian records indicate that the laborers, while being drafted against their will, were actually well cared for by ancient standards. Regulations have been found covering the maximum amount of work allowed per day, the wages received and holidays entitled to, each worker. By only requiring work to be done during flood periods, the Pharaoh could get a lot done without impacting the normal Egyptian economy.
He probably also employed a much smaller work force year round on the project. Some would have been employed doing the skilled stonework while others planned and prepared the site for the laborers that would be available during the next flood season.
The shape of the pyramid are the logical one for producing buildings of great height when the building material available is stone. The design mimics the natural geometry of a mountain, an incline of about 52 degrees. The Egyptian architects realized the ever widening base would easily support the increasing number of stone blocks above it making the structure very stable.
An average 2 and 1/2 ton limestone block used in the pyramid construction would have probably taken 8 men nine or ten days to move from the quarry, float across the Nile, and drag to the top of the pyramid.
The most likely method of getting the blocks to the top of the structure was through massive construction ramps. Exactly how the ramps were laid out is unknown, but they may have been straight or in a spiral pattern around the pyramid. The ramps may have been topped with a surface of Tafla, a clay. Tafla, when wet, becomes very slippery and may have allowed the Egyptian builders to use shorter, steeper ramps than might have otherwise been possible. By wetting the ground in front of the block a slick path would be created allowing the stone to be dragged by rope as it sat on sledges.
It is also possible the stones could have been moved on rollers. By placing rounded logs under the stone, crude wheels would have made the load easy to pull. Pictures inscribed on ancient monument walls, though, suggest the blocks were dragged without the aid of rollers. Once a stone was at the top of the pyramid, it was probably moved into its final position with the use of levers. We can see the Egyptains didn't become great pyramid builders right away. They needed some practice. They started by cutting tombs into the rock of the desert floor and building mastabas (from the Arab word meaning "bench") over them. Mastabas were raised, flat, platforms. Some were twenty-five feet high and two-hundred feet square. Imhotep, architect to the Pharaoh Zoser, changed this by building his king a mastaba and then placing another, smaller mastaba right on top of it. On top of that he placed another even smaller mastaba. When he was finally done the structure had six levels and resembled a stepped pyramid.
A number of stepped pyramids were built after that, but the most interesting is the one at Meidum built for Pharaoh Seneferu. It's an example of an early design that failed. The pyramid, which has four levels, is in near ruins today with many of its blocks laying in a heap around the base. Why did it do so poorly when many other pyramids are in much better shape? The architect of this pyramid apparently had not yet learned the importance of laying the foundation on solid rock rather than sand. Also, the construction trick of tilting the blocks on a slope inward toward the center of the pyramid had not been invented. By tilting the blocks slightly inward, the weight of the blocks helped lock them into the structure.
Without this trick and with a poor foundation, the pyramid at Meidum was easily shaken apart during earthquakes. Later, better built pyramids show that the Egyptians learned as they built and their masterpieces have stood the test of the centuries.
More About Pyramid : Introduction : What is Pyramid : How to built Pyramid : Pyramid History : Khufu's Great Pyramid : Photo Gallery