Petroski on Engineering: Engineering & Civilization

Engineering and civilization have always gone together, it is difficult to imagine one existing without the other. Indeed, we tend to associate ancient civilizations specifically with their technological achievements, which, in many cases, remain as monuments to the culture. The Pyramids are a most prominent example. The first engineer whose name is known to us was the Egyptian Imhotep, who is credited with the design of massive piles of stones as burial structures.

After millennia, the Pyramids still stand as awesome symbols of engineering design and construction. Although the processes by which the great edifices were realized remain topics of considerable speculation and debate, there is no denying that it took an engineering imagination to conceive of and lay out the elegant external and complex internal structures, and to devise and execute the necessary systems of transporting to the construction site large numbers of stones and lifting them into place in an orderly fashion.

Roman engineering achievements are no less remarkable. The towering aqueducts that still stand may be the most visible manifestations of highly developed and reliable water distribution systems, but the integrated component parts consisting of tunnels, pipes, valves, baths, and drains were all designed to achieve their individual ends and contribute to the overall plan.

While no documents give us detailed information on how the Egyptians accomplished their great engineering projects, the two-millennia-old Ten Books on Architecture by the Roman architect/engineer Vitruvius gives us considerable insight into how ancient engineering was practiced. One of the most remarkable aspects of this oldest surviving book on engineering is how it demonstrates that the way engineers thought about design in ancient times appears to have been fundamentally the same as how we think today, and in their technological context the problems with which the Romans dealt could be as thorny as those we know today.

As is evident in Vitruvius’s Ten Books -- still eminently readable for such an old treatise -- ancient architects and engineers wrestled with design problems defined by competing goals and bounded by technical and nontechnical constraints, including economic ones. Vitruvius describes how the architects and engineers of his time had to be masters of a wide variety of knowledge and skill -- essentially, they had to be broadly interdisciplinary people, something we hear expressed often today.

Greek architecture was obviously aesthetically distinct from Roman, but as Vitruvius made clear, underlying engineering principles were common to both. The design of structures in ancient times was based on geometry, with the Romans favoring the semicircular arch and hemispherical dome as a basic building unit and the Greeks employing mainly post-and-lintel construction. Whichever form was used to build in stone, ancient engineers found limits of use defined by failure.