The Colosseum or Coliseum, also known as the Flavian Amphitheatre is an elliptical amphitheater in the center of the city of Rome, Italy. Near Labicana valley. 

Construction started: 70 AD Opened: 80 AD Function: Amphitheater Architectural style: Ancient Roman architecture Architects: Vespasian, Titus It took about ten years to build the amphitheatre

Its long axis, oriented WNW-ESE, measures 188 metres and the short one 156.The overall height of the building is 48,5 metres (159’)The arena measures 76 m by 44 (249 by 144 feet, or 83 by 48 yard)The building stands on a base of 2 steps; there are 3 floors of arcades and a 4th story with windows .There were 80 arches on every floor, divided by pillars with a half column. The Colosseum contained 45,000 sitting places and 5,000 standing places.

FACTS ABOUT THE COLOSSEUM

After the death of Nero in 68 AD,  Vespasian  came to power and established a new dynasty: the Flavians, emperors Vespasian, Titus and Domitian between 71-72 and 80 AD as a gift to the Roman citizens in the place where showing that the times of tyranny and despotism were over: He made a point of giving back the area of Nero’s Domus Aurea to the Romans.

The amphitheater then – a public building donated by the emperor to the Roman citizens – stood on the former site of Nero’s mansion as a symbol of the new political order.

The area previously was a lake, but it was drained during the building of Nero’s palace. The area still was marshy after heavy rains, therefore a perfect drainage system had to be constructed.

After the area was completely drained, the excavation started, and it lasted until it reached the clay bed of the lake. In the firm clay bed an elliptical ring was excavated, 31 metres wide, 6 metres deep, with a perimeter of 530 meters.

This enormous excavation was filled up with Roman cement, mixed with coarse crushed stones. Layers and layers of mortar and stones were laid, and the concrete was compacted by hammering. It seems that on the SW side the clay bed wasn't as firm as on other sides, and this could be the reason why that side collapsed first.

The colosseum is generally supposed to be elliptical, but the curve of the arena and of the remaining facade, which has now been measured to a high degree of accuracy, does not coincide exactly with a perfect ellipse. It is in fact an ovoid (a polycentric curve, i.e. a curve with more than one center), but very approximate to an ellipse.

Also, there are really esoteric explanations of the geometry of the Colosseum, like the triangle with proportions 3:4:5 (which in the case of the Colosseum becomes 6:8:10),

The solution should be found by measuring the building with a high degree of precision ,has faced many obstacles to it: the original small deviations of stones and brickwork from the plan as a result of the general deformation of the structures, due to earthquakes, land movements etc., then the ruined state of the stones, etc,hence body can demonstrate in full the validity of his theory.

Most archeologists believe was made from polycentric curves because:

First, it has been adopted for amphitheaters all over the Empire.

Secondly, it is easy to draw with simple instruments that the  (land surveyors) used every day to measure land and make plans for roads and buildings.

Moreover, if a polycentric curve has a minimum number of centers e.g. 4 it is almost indistinguishable from an ellipse.

According to the famous Colosseum expert,  Ingegner Giuseppe Cozzo, the hypothesis is that the curve of the arena is a polycentric one, i.e. a curve composed of many different curves, whose centers are found by means of a geometric system.

The first tier was decorated in Doric columns, the second in Ionian columns, and the third in Corinthian columns.

  Over many centuries, two-thirds of the Colosseum has been removed to build several churches and palaces.

Doric columns

IONIC COLUMN CORINTHIAN COLUMN

The first repairs were probably made during emperor Antonius Pius (86-161), as proven by one Corinthian capital of a column of that age found by the archaeologists, after a fire had destroyed 350 houses in the city.

Major repairs, actually an almost complete rebuilding, were carried out after 217 AD, the year in which the upper floor was struck by lightning and went on fire. The embers set alight the wooden floor of the arena that in turn collapsed igniting the wooden structures beneath it and the rest of the building.

It took more than thirty years to rebuild the Roman amphitheatre

As a result of this plunder, and also because of fires and earthquakes, two thirds of the original have been destroyed, so that the present Colosseum is only a shadow of its former self, a noble ruin

 Romans start taking the iron clamps that held blocks together and looting stone from the Colosseum. Pope Alexander VI even leased it out as a quarry, collecting one-third of the profits.

It was not until 1749 that Pope Benedict XIV forbade the removal of stone from the structure, consecrating the arena to the Christian martyrs who died there and erecting a cross in the center. Later popes initiated various restoration projects, reinforcing the façade and removing the extensive vegetation which had overgrown the structure and threatened to damage it further.

Today it is a tourist attraction,with a museum at the top

the-colosseum.net The Wikipedia

BY;

GITAU JAMES KENNEDYB02/0886/2013