| [Visitor (58.214.*.*)]answers [Chinese ] | Time :2023-01-03 |  The structure of the Pantheon is simple and clear, with a circular body and covered by a dome with a diameter of 43.3 meters, the largest dome between its construction and 1436. The highest point of the dome is also 43.3 meters, and at the top there is a large circular hole with a diameter of 8.9 meters for lighting.
The Pantheon adopts a centralized form covered by a dome, and the reconstructed Pantheon is a representative of a single-space, centralized composition of the building, which is also the highest representative of Roman dome technology. The Pantheon is circular in plan, with a dome diameter of 43.3 meters and a height of 43.3 meters at the top.
According to the concept of the time, the dome symbolized the sky. A round hole with a diameter of 8.9 meters in the center of the dome may indicate some connection between the world of God and the world of man. The soft diffuse light coming in from the round cave illuminates the empty interior, and there is a religious tranquility. The outside of the dome is covered with a layer of gilded copper tiles. (In the 8th century, Pope Gregory III covered with lead tiles)
The material of the dome is concrete, there are bricks, and the concrete is made of pumice stone as an aggregate. Probably a few large coupons were first built with bricks along the spherical surface, and then concrete was poured. The purpose of these coupons is to pour the concrete in sections, prevent the concrete from sliding before setting, and avoid cracks when the concrete shrinks.
In order to reduce the weight of the dome, it becomes thinner the higher up, the lower part is 5.9 meters thick and the upper part is 1.5 meters. And make five deep recesses on the inner surface of the dome, 28 in each circle.
The walls are 6.2 meters thick and also concrete. For every 1 meter or so poured, 1 layer of large bricks is laid. Inside the wall, 8 large coupons are issued along the circumference, of which 7 are niches and one is a gate. Niches and gates also reduce the burden on the foundation. The foundation is 4.5 meters deep and the base thickness is 7.3 meters. The concrete of the foundation and walls is made of tuff and travertine as aggregates.
The portico of the Pantheon is tall and majestic, but also ornate and flashy, representing the typical style of Roman architecture. It is 33 meters wide on the façade and has a rectangular colonnade on the front, which is 34 meters wide and 15.5 meters deep; There are 16 Corinthian stone pillars, divided into three rows, 8 in the front row, 4 in the middle and 4 in the back. The column is 14.18 meters high and 1.43 meters in base diameter and is machined from a single block of Egyptian gray granite.
The capitals and bases are white marble. Statues of mountain flowers and cornices, gate leaves, tiles, ceiling beams and slabs in the porch, are all made of copper and covered with gold leaf. The world record for the Great Dome of the Pantheon, with a diameter of 43.3 meters, was not broken until 1960 by the construction of the new Grand Dome of the Coliseum with a diameter of 100 meters in Rome.
The façade is divided into 3 floors, the lower layer is plastered with white marble, the upper two are plastered, and the third floor may be decorated with thin pilasters. The lower two floors are walls, and the third layer encloses the lower part of the dome, so the dome is not fully expressed. This is presumably to: first, to reduce the influence of the lateral thrust of the dome; Second, raise the wall to make the body shape more symmetrical; Thirdly, there was no artistic experience of dealing with full domes at that time, nor did they have such aesthetic habits.
The temple itself is rectangular in shape on the front, circular in plan, and a domed hall with 8 huge arched pillars inside. The largest dome in the ancient world is 43.3 meters in diameter, with a bright eye with a diameter of 8.92 meters, making it the only entrance to the entire building. The diameter and height of the hall are also 43.3 meters, and the surrounding walls are 6.2 meters thick, and the exterior is made of huge bricks, but there are no windows and no columns.
It is said that the Pantheon was the first Roman building to pay more attention to the interior than the exterior, but some of the original bronze and marble carvings were lost to foreign plundering or transferred to later Roman buildings, and the magnificent red stone on the outside has disappeared and lost its former charm. The two bronze gates at the entrance of the temple are still originals, and the doors are 7 meters high, wide and thick, making them the largest bronze doors in the world at that time.
Internal structure
Upon entering, visitors are greeted by a huge circular room with a dome inside. The eye holes at the top of the dome were never covered, allowing rainwater to flow from the ceiling to the floor. Because of this, the interior floor is equipped with gutters and built with an inclination of about 30 cm (12 inches) to promote water runoff.
The interior of the dome was probably meant to symbolize the vaulted vault of heaven. The eye holes and entrance at the top of the dome are the only natural light sources in the room. Throughout the day, light from the eyeball moves through this space in the opposite sundial effect: time is marked with light rather than shadow. The eyes also provide cooling and ventilation; During storms, a drainage system under the floor can handle rainwater falling from the eyeholes.
The dome is characterized by concave panels (vaults) with five rings of 28 each. This evenly distributed layout is difficult to achieve, presumably symbolic, whether numerical, geometric, or moon. In ancient times, vaults may contain bronze rosettes symbolizing the starry sky.
Circles and squares form the unifying theme of interior design. The checkerboard floor pattern contrasts with the concentric circles of the square vault in the dome. Each area of the interior, from floor to ceiling, is subdivided according to different schemes. As a result, the interior decoration areas are not aligned.
The overall effect is to observe the direction of the viewer directly according to the main axis of the building, even if the cylindrical space with a hemispherical dome at the top is inherently ambiguous. This inconsistency was not always taken seriously, and the attic level was redesigned in the 18th century according to neoclassical tastes. |
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