The Pantheon, Rome: dome and oculus
Rome was the first foreign city I ever visited on my own, and among the many memorable sights and sites I remember being most astonished by the Pantheon, simply because it is by far the oldest Roman building that is not a ruin and is still in use.
Though the inscription on the pediment suggests it was built by Marcus Agrippa (64/62BC-12BC), the existing structure, apart from the façade, is in fact a rebuilding by the Emperor Hadrian (76AD-138AD) dating from 118AD-128AD.
The interior is a remarkable space, a cylinder surmounted by a coffered dome which rises to a circular oculus, open to the skies. This is the only source of light – there are no windows – and when it rains the water drains away beneath the floor.
The proportions are mathematically exact: the footprint forms a square in plan and elevation that equals the height of the oculus, 150 Roman feet (142 Imperial feet or 43.3 metres). This means that a sphere 142 feet in diameter would fit exactly within the dome.
The name Pantheon indicates that this may have originally been a temple “dedicated to all the gods”. It survived because in 609AD Pope Boniface IV converted it to a church dedicated to St Mary and the Martyrs.
It has remained a place of Christian worship ever since, and is the burial place of, among others, the painter Raphael (1483-1520), the composer Arcangelo Corelli (1653-1713) and two Italian monarchs, Victor Emmanuel II (1820-1878, king of Sardinia until 1861 and afterwards the first king of Italy) and his son and successor Umberto I (1844-1900).
Apart from its long history and survival, the Pantheon’s great significance is its influence on Western architecture. Square – and sometimes circular – Classical buildings with cylindrical interiors and portico entrances are ubiquitous.
The great Italian architect Andrea Palladio produced variations on the theme, such as the church of Il Redentore (1577-92) in Venice, where he was obliged to lengthen the nave and, near Vicenza, his magnificent Villa Capra (designed 1566-7) and the Tempietto Barbaro (designed 1580).
Paris has its Panthéon, built as a church between 1758 and 1790. There is a Pantheon in the garden at Stourhead, Wiltshire (1756). The interior of the Marble Saloon at Stowe House, Buckinghamshire (1788) is directly based on the Roman original
Thomas Jefferson, whose own plantation house, Monticello (1772), echoes the Roman Pantheon, designed a more precise reproduction as the Rotunda library at the University of Virginia (1822-6) and his own memorial in Washington DC, designed by John Russell Pope in 1935, follows the same form.
Manchester’s Central Library, designed by Vincent Harris and built 1930-34, follows the same pattern.
There are many such buildings across the world, and they all refer back to the original in Rome.