The rampart, the vault and the dome: The itinerary of an idea through several millennia

In the early part of his sedentary existence, man was constantly brought up against the same problem: the building of solid structures with sheer faces – defences against invaders or platforms to support temples or palaces – and thus the necessity of containing the lateral thrust. We have already seen how the Sumerians solved this problem by incorporating mats and cables which countered these forces. An alternative approach soon emerged, the wall reinforced with counterforts, an idea which was elegantly carried into effect by the Attalids at Pergamum (second century b.c.) for the retaining wall of the terrace on which the temple of Demeter stood. This wall is 85 m long and 14 m high, with internal and external counterforts evenly spaced along its length ( Figure 44 ). Later, in his ‘De Re Architectura’, Vitruvius would give a clear statement of the principles involved: