Great Pyramid of Giza

The Great Pyramid of Giza (also known as the Pyramid of Khufu or the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza pyramid complex bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact.

Based on a mark in an interior chamber naming the work gang and a reference to fourth dynasty Egyptian Pharaoh Khufu, Egyptologists believe that the pyramid was built as a tomb over a 10 to 20-year period concluding around 2560 BC. Initially at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for more than 3,800 years. Originally, the Great Pyramid was covered by casing stones that formed a smooth outer surface; what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories about the Great Pyramid's construction techniques. Most accepted construction hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.

There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called Queen's Chamber and King's Chamber are higher up within the pyramid structure. The main part of the Giza complex is a setting of buildings that included two mortuary temples in honour of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles.

It is believed the pyramid was built as a tomb for Fourth Dynasty Egyptian pharaoh Khufu (often Hellenicised as "Cheops") and was constructed over a 20-year period. Khufu's vizier, Hemon, or Hemiunu, is believed by some to be the architect of the Great Pyramid. It is thought that, at construction, the Great Pyramid was originally 280 Egyptian cubits tall (146.5 metres (480.6 ft)), but with erosion and absence of its pyramidion, its present height is 138.8 metres (455.4 ft). Each base side was 440 cubits, 230.4 metres (755.9 ft) long. The mass of the pyramid is estimated at 5.9 million tonnes. The volume, including an internal hillock, is roughly 2,500,000 cubic metres (88,000,000 cu ft). Based on these estimates, building the pyramid in 20 years would involve installing approximately 800 tonnes of stone every day. Additionally, since it consists of an estimated 2.3 million blocks, completing the building in 20 years would involve moving an average of more than 12 of the blocks into place each hour, day and night. The first precision measurements of the pyramid were made by Egyptologist Sir Flinders Petrie in 1880–82 and published as The Pyramids and Temples of Gizeh. Almost all reports are based on his measurements. Many of the casing stones and inner chamber blocks of the Great Pyramid fit together with extremely high precision. Based on measurements taken on the northeastern casing stones, the mean opening of the joints is only 0.5 millimetre wide (1/50 of an inch).

Great Pyramid of Giza from a 19th-century stereopticon card photo
The pyramid remained the tallest man-made structure in the world for over 3,800 years, unsurpassed until the 160-metre-tall (520 ft) spire of Lincoln Cathedral was completed c. 1300. The accuracy of the pyramid's workmanship is such that the four sides of the base have an average error of only 58 millimetres in length. The base is horizontal and flat to within ±15 mm (0.6 in). The sides of the square base are closely aligned to the four cardinal compass points (within four minutes of arc) based on true north, not magnetic north, and the finished base was squared to a mean corner error of only 12 seconds of arc. The completed design dimensions, as suggested by Petrie's survey and subsequent studies, are estimated to have originally been 280 royal cubits high by 440 cubits long at each of the four sides of its base. The ratio of the perimeter to height of 1760/280 royal cubits equates to 2π to an accuracy of better than 0.05% (corresponding to the well-known approximation of π as 22/7). Some Egyptologists consider this to have been the result of deliberate design proportion. Verner wrote, "We can conclude that although the ancient Egyptians could not precisely define the value of π, in practice they used it". Petrie, author of Pyramids and Temples of Gizeh concluded: "but these relations of areas and of circular ratio are so systematic that we should grant that they were in the builder's design". Others have argued that the Ancient Egyptians had no concept of pi and would not have thought to encode it in their monuments. They believe that the observed pyramid slope may be based on a simple seked slope choice alone, with no regard to the overall size and proportions of the finished building.

In 2013 rolls of papyrus were discovered written by some of those who delivered stone and other construction materials to Khufu's brother at Giza.

Many alternative, often contradictory, theories have been proposed regarding the pyramid's construction techniques. Many disagree on whether the blocks were dragged, lifted, or even rolled into place. The Greeks believed that slave labour was used, but modern discoveries made at nearby workers' camps associated with construction at Giza suggest that it was built instead by tens of thousands of skilled workers. Verner posited that the labour was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 20,000 men each, which may have been further divided according to the skills of the workers.

One mystery of the pyramid's construction is its planning. John Romer suggests that they used the same method that had been used for earlier and later constructions, laying out parts of the plan on the ground at a 1-to-1 scale. He writes that "such a working diagram would also serve to generate the architecture of the pyramid with precision unmatched by any other means". He also argues for a 14-year time span for its construction.

A modern construction management study, in association with Mark Lehner and other Egyptologists, estimated that the total project required an average workforce of 14,567 people and a peak workforce of 40,000. Without the use of pulleys, wheels, or iron tools, they used critical path analysis to suggest that the Great Pyramid was completed from start to finish in approximately 10 years.

The original entrance to the Great Pyramid is 17 metres (56 ft) vertically above ground level and 7.29 metres (23.9 ft) east of the center line of the pyramid. From this original entrance, there is a Descending Passage 0.96 metres (3.1 ft) high and 1.04 metres (3.4 ft) wide, which goes down at an angle of 26° 31'23" through the masonry of the pyramid and then into the bedrock beneath it. After 105.23 metres (345.2 ft), the passage becomes level and continues for an additional 8.84 metres (29.0 ft) to the lower Chamber, which appears not to have been finished. There is a continuation of the horizontal passage in the south wall of the lower chamber; there is also a pit dug in the floor of the chamber. Some Egyptologists suggest that this Lower Chamber was intended to be the original burial chamber, but Pharaoh Khufu later changed his mind and wanted it to be higher up in the pyramid.

At 28.2 metres (93 ft) from the entrance is a square hole in the roof of the Descending Passage. Originally concealed with a slab of stone, this is the beginning of the Ascending Passage. The Ascending Passage is 39.3 metres (129 ft) long, as wide and high as the Descending Passage and slopes up at almost precisely the same angle. The lower end of the Ascending Passage is closed by three huge blocks of granite, each about 1.5 metres (4.9 ft) long. At the start of the Grand Gallery on the right-hand side there is a hole cut in the wall. This is the start of a vertical shaft which follows an irregular path through the masonry of the pyramid to join the Descending Passage. Also at the start of the Grand Gallery there is the Horizontal Passage leading to the "Queen's Chamber". The passage is 1.1m (3'8") high for most of its length, but near the chamber there is a step in the floor, after which the passage is 1.73 metres (5.7 ft) high.

Colossus of Rhodes

The Colossus of Rhodes was a statue of the Greek titan-god of the sun Helios, erected in the city of Rhodes, on the Greek island of the same name, by Chares of Lindos in 280 BC. One of the Seven Wonders of the Ancient World, it was constructed to celebrate Rhodes' victory over the ruler of Cyprus, Antigonus I Monophthalmus, whose son unsuccessfully besieged Rhodes in 305 BC. Before its destruction in the earthquake of 226 BC, the Colossus of Rhodes stood over 30 metres (98 feet) high, making it one of the tallest statues of the ancient world.

Construction began in 292 BC. Ancient accounts, which differ to some degree, describe the structure as being built with iron tie bars to which brass plates were fixed to form the skin. The interior of the structure, which stood on a 15-metre (49-foot) high white marble pedestal near the Mandraki harbour entrance, was then filled with stone blocks as construction progressed. Other sources place the Colossus on a breakwater in the harbour. The statue itself was over 30 metres (98 feet) tall. Much of the iron and bronze was reforged from the various weapons Demetrius's army left behind, and the abandoned second siege tower may have been used for scaffolding around the lower levels during construction. Upper portions were built with the use of a large earthen ramp. During the building, workers would pile mounds of earth on the sides of the colossus. Upon completion all of the earth was removed and the colossus was left to stand alone. After twelve years, in 280 BC, the statue was completed. Preserved in Greek anthologies of poetry is what is believed to be the genuine dedication text for the Colossus.

Construction

The Colossus of Rhodes as imagined in a 16th-century engraving by Martin Heemskerck, part of his series of the Seven Wonders of the World.
To you, O Sun, the people of Dorian Rhodes set up this bronze statue reaching to Olympus, when they had pacified the waves of war and crowned their city with the spoils taken from the enemy. Not only over the seas but also on land did they kindle the lovely torch of freedom and independence. For to the descendants of Herakles belongs dominion over sea and land.

Modern engineers have put forward a plausible hypothesis for the statue construction, based on the technology of those days (which was not based on the modern principles of earthquake engineering), and the accounts of Philo and Pliny who both saw and described the remains.

The base pedestal was at least 60 feet (18 m) in diameter and either circular or octagonal. The feet were carved in stone and covered with thin bronze plates riveted together. Eight forged iron bars set in a radiating horizontal position formed the ankles and turned up to follow the lines of the legs while becoming progressively smaller. Individually cast curved bronze plates 60 inches (1,500 mm) square with turned-in edges were joined together by rivets through holes formed during casting to form a series of rings. The lower plates were 1 inch (25 mm) in thickness to the knee and 3/4 inch thick from knee to abdomen, while the upper plates were 1/4 to 1/2 inch thick except where additional strength was required at joints such as the shoulder, neck, etc.

Destruction

The statue stood for 54 years until Rhodes was hit by the 226 BC earthquake, when significant damage was also done to large portions of the city, including the harbour and commercial buildings, which were destroyed. The statue snapped at the knees and fell over onto the land. Ptolemy III offered to pay for the reconstruction of the statue, but the oracle of Delphi made the Rhodians afraid that they had offended Helios, and they declined to rebuild it.

The remains lay on the ground as described by Strabo (xiv.2.5) for over 800 years, and even broken, they were so impressive that many travelled to see them. Pliny the Elder remarked that few people could wrap their arms around the fallen thumb and that each of its fingers was larger than most statues.

In 653, an Arab force under Muslim caliph Muawiyah I captured Rhodes, and according to The Chronicle of Theophanes the Confessor, the statue was cast down and sold to a Jewish merchant of Edessa who loaded the bronze on 900 camels. The Arab destruction and the purported sale to a Jew possibly originated as a powerful metaphor for Nebuchadnezzar's dream of the destruction of a great statue.

Tutankhamun's mask

Tutankhamun's mask, also known as the funerary mask of Tutankhamun, is the death mask of the Ancient Egyptian pharaoh, Tutankhamun (reigned 1332–1323 BC). It was discovered by Howard Carter in 1925 in tomb KV62, and is now housed in the Egyptian Museum in Cairo. The mask is one of the most well known works of art in the world. According to the Egyptologist Nicholas Reeves, it is "not only the quintessential image from Tutankhamun's tomb, it is perhaps the best-known object from ancient Egypt itself". Since 2001, research has suggested that the mask may originally have been intended for Queen Neferneferuaten; her royal name (Ankhkheperure) was found in a partly erased cartouche on Tutankhamun's funerary mask.

The mask is 54 cm (21 in) tall, 39.3 cm (15.5 in) wide and 49 cm (19 in) deep. It is fashioned from two layers of high-karat gold, varying from 1.5–3 mm (0.059–0.118 in) in thickness, and weighing 10.23 kg (22.6 lb). X-ray crystallography has revealed that the mask contains two alloys of gold: a lighter 18.4 karat shade for the face and neck, and 22.5 karat gold for the rest of the mask.

The face represents the pharaoh's standard image, and the same image was found by excavators elsewhere in the tomb, in particular in the guardian statues. He wears a nemes headcloth, topped by the royal insignia of a cobra (Wadjet) and vulture (Nekhbet), symbolising Tutankhamun's rule of both Upper and Lower Egypt. The ears are pierced to hold earrings, a feature that appears to have been reserved for queens and children in almost all surviving ancient Egyptian works of art.

It contains inlays of coloured glass and gemstones, including lapis lazuli (the eye surrounds and eyebrows), quartz (the eyes), obsidian (the pupils), carnelian, feldspar, turquoise, amazonite, faience and other stones (as inlays of the broad collar).