Domes at the turn of the millennium

Abstract

The domical shape has been preferred as roofing from the very beginning. However, the first climax was reached only at the beginning of the 1st millennium during the Roman Empire, Pantheon from 128 A.D. being the largest dome ever erected in masonry for more than a millenium. On the other hand in Hagia Sophia to the central dome pendentives and semi-domes were added to cover an oblong space with masonry. During the first half of the 2nd millennium in Islamic countries and with Renaissance also in Europe the double dome was preferred, whereas the Ottoman building-masters, especially Mimar Sinan, has developed the combination of large and small domes with semi-domes to perfection. In the 19th century the era of metallic domes starts, whereas in the 20th century until the sixties reinforced concrete shell type domes dominate. Recently preference is given to reticulate structures and membranes which are unfortunately, not as durable as masonry.