Vaulting ambition.

CONCRETE VAULTED CONSTRUCTION IN IMPERIAL ROME: INNOVATIONS IN CONTEXT

By Lynne C. Lancaster. Cambridge: Cambridge University Press. 2005. [pounds sterling]55

This substantial work pulls together research and analysis of vaulted buildings constructed in or around Rome from 27 BC to AD 330. It is an interdisciplinary study, and the author (who is an architect turned Classical Archaeology scholar) has drawn on fellow academics' expertise in engineering and geology. Much of it is highly technical. One appendix describes how you can carry out your own 'thrust line analysis' of an arch, while another tabulates Lancaster's analysis of rubble samples from key buildings to show that building materials were being imported into Rome from Vesuvius throughout the study period. Despite the inclusion of statements such as 'all contain sanidine in the groundmass as well as significant amounts of plagioclase ... the presence of olvine and the lack of phenocrysts of sanidine rules out the Sabatini system' (a conclusion of the rubble study), the book aims to serve both a specialist and a general reader, and is generally successful in this.

For instance, it's an easy one-liner to say that the Romans invented concrete, but, as Lancaster points out, the Roman material is 'different from what we think of today as concrete'. It was not a homogeneous mix, which could be poured in place, but rather layers of rubble held together with mortar, the two ingredients laid separately. Many of the structures studied, including the Pantheon and the Baths of Trajan and Caracalla, are well known and much visited and the argument that Lancaster makes for why they came about is compelling and accessible. She accesses the situation in terms of four criteria for technological innovation previously applied to the study of agricultural development. These are 'accumulated knowledge', 'evident need', 'economic possibility' and 'cultural/social/political acceptability'--and Rome had them all. It was the contemporaneous development of the arch and discovery of pozzolana mortar, with a new need for large gathering spaces for social institutions, and the availability of wealth from conquests and taxation which provided the wherewithal for buildings that met a compelling 'desire to match the architectural accomplishments of conquered territories in the Hellenistic Greek world'. As Lancaster summarises it, 'In Imperial Rome, all the natural advantages and cultural influences came together and manifested themselves in imposing concrete vaulted structures'.

So what can the twenty-first century architect get from this study? Lancaster notes that it was as an admirer of Louis Kahn that she was first drawn to look at Roman brick arches. These had inspired him when he was at the American Academy in Rome in 1950. But clearly for Kahn it was a visceral and aesthetic response which fuelled his imagination; he certainly did not have the detailed knowledge displayed here and in fact may have had all sorts of misconceptions. For instance Lancaster notes her own initial attraction to an 'honesty' in the use of materials but adds that she now realises that the Romans 'were probably not remotely interested in this modernist concept'.

This is a rigorous fascinating study, and excellent background for a trip to Rome, rather than a pictorial source book.

Book reviews from The Architectural Review can now be seen on our website at www.arplus.com and the books can be ordered online, many at special discount.