Maritime Technology in the Ancient Economy: Ship-Design and Navigation

Given the long-standing discussion of social embeddedness in the ancient economy, it seems only natural that studies addressing Mediterranean economic institutions and change should consider the impact of another socially constructed phenomenon: technology. While Greek and Roman technology was once viewed as generally static and unproductive, a growing corpus of studies has now demonstrated the socioeconomic effects of innovations in fields ranging from hydraulic engineering to mining and manufacturing. Yet within discussions of maritime trade, it is startling that the technologies associated with shipping have prompted little critical economic analysis, particularly in light of widespread acknowledgment that certain obvious technological changes related to seafaring did occur—in methods of ship construction as well as types of sails and rigging. The corollary question is obvious but hardly straightforward: what, if any, economic impact can we attribute to changes in maritime technology?

This unique volume, edited by Harris and Iara, collects a range of perspectives on this question. It represents the outcome of a conference, held in Rome in 2009, that brought together ship experts and economic historians. The event and proceedings pose a formidable query, asking “whether advances in either ship-construction or navigation are likely to have lowered the costs of maritime trade at any time during the longue durée of the Graeco-Roman Mediterranean” (9). Integration of these often disparate fields presents a daunting challenge but follows admirably in the tradition of Casson and D’Arms, to whom the volume is appropriately dedicated. To this end, several papers represent new looks at old problems of naval carpentry, ship size, and the technologies associated with seafaring knowledge. Others tackle topics related to purpose-built boats, specialized environments, and seasonality, which lead the volume happily beyond the confines of ship construction and navigation. The 14 contributions—8 in English, 4 in Italian, and 2 in French—survey broadly while maintaining their common focus on the fundamental socioeconomic question. Many readers will be inclined to turn immediately to those chapters that most directly address their particular chronological or material interests. Yet a common bibliography and index invite readers to wander through broader themes and to explore more widely.

Three contributions frame the book and define a recurrent theme throughout its pages: the comparative roles of institutions and technology in economic performance. Harris’ introduction establishes the parameters for the discussion by laying bare many shortcomings of the evidence, weaving together several major focuses of the contributions and providing a broad outline of some of the more secure developments in maritime technology that may have influenced economics. Scheidel then turns to the New Institutional Economics for explanations of Rome’s flourishing maritime trade, suggesting that any major gains at sea were the result not so much of technological improvements but of the imperial state, whose stability lowered impediments and costs to commerce. In the concluding chapter, Wilson posits a somewhat stronger role within this institutional framework for technological developments in facilitating economic gains. He characterizes improvements in ship construction, equipment, and harbor facilities as technological prerequisites that allowed larger ships, safer journeys, and new routes. These contributions from three prominent Romanists underscore the volume’s decidedly Roman flavor, even if discussions by Harris and others routinely reach back to archaic and classical Greece for the origins of key technologies under analysis.

Eleven papers at the core of the volume explore an impressive (but by no means exhaustive) range of technologies; some authors’ evaluations highlight innovation and adaption, while others offer a largely static view. The complex interplay of economy and technology, however, is not always afforded the same detail. For example, while the broad impact of technology on economy is naturally the common theme, comparatively few explore the extent to which economic demand actually drove technological development. Reading the Stadiasmus as a more practical handbook than most earlier periploi, Medas reasonably concludes that commercial organizations may have played a role in compiling documents for training and logistics (176). In other contributions, economic drivers are more often intimated than demonstrated. Likewise, the economic gain of certain innovations is sometimes less clear, and the explicit nature of an “improvement” is occasionally left ambiguous or framed simply as linear evolution. In part, this may be a result of our limited evidence, which at present makes it difficult enough to understand when and how certain technologies functioned, leaving aside the more probing questions of who chose what technology, in what circumstances, and to what practical effect.

Even so, there are reassuring signs among a number of contributions that the wider socioeconomic context is becoming all the more central as we map maritime technology’s influence in a nonlinear way. Tchernia’s typology of commercial ventures stresses the remarkably heterogeneous nature of Roman shipping (88), which surely reflects not only the diverse interests and technological choices of mariners themselves but also the various socioeconomic contexts behind this exchange. Politics appear routinely in these pages. It was political as much as economic interest that prompted Boetto’s specialized caudicariae to lug cargoes up the Tiber and determined the placement of Red Sea ports analyzed by Cooper. Yet other factors are likewise beginning to emerge from the shadows. Here I note Whitewright’s cogent reevaluation of one important (and apparently long-misunderstood) technology whose development did not represent a simple march of progress. He argues that the lateen sail, whose popularity grew from the Roman period into late antiquity, offered neither greater speed nor better performance into the wind (92). If correct, this surprising realization necessitates an alternative explanation for its use within some circles, but it also allows us to understand its adoption or rejection as an active and socially constructed choice. How might a new sail and rigging configuration have changed the organization of labor on a vessel? To what degree did the shapes of sails alongside their markings signal geographical, ethnic, or other cultural associations?

One particularly well-known change bridges various chapters and illustrates the dynamic interaction of technology, economy, and other factors with which the authors must wrestle: the adoption of mortise-and-tenon joinery. While this technology was known from at least the Bronze Age, it was probably only around the sixth century B.C.E. that Greek shipwrights employed it in the construction of sturdier hulls and, by extension, larger ships capable of handling bigger cargoes than their earlier sewn/laced vessels. If we apply Harris’ yardstick for measuring a technology’s economic impact—its relatively rapid widespread adoption (15)—we arrive at a dilemma, for mortise-and-tenon construction was neither quickly nor completely adopted. The continued success of sewn/laced boat knowledge is evident both in the centuries of repairs to otherwise mortise-and-tenon built vessels and in its survival among some groups of mariners into the Roman era and beyond. Despite some obvious advantages, this new technique was also more labor and material intensive, and hence more expensive. Its economic impact depended on the agency of different merchant mariners across the Mediterranean, who would have chosen or rejected it according to its utility, price, and adaptability, as well as their specific circumstances, environment, traditions, knowledge base, interests, and resources. The flexibility of a sewn/laced vessel may have offered a distinct advantage for mariners who needed to beach their hulls outside the larger harbors. If the innovative spark hypothesized by Pomey (and others previously) has merit—that a need for stronger warship hulls able to ram and absorb the impact of enemy rams led to mortise-and-tenon construction (52–3)—then economic necessity was not the mother of this invention. Any economic benefits from stronger mortise-and-tenon joinery were a by-product of innovation driven not by price-conscious merchants but by the state’s military interests and ability to mobilize resources and personnel.

If none of the technologies investigated here revolutionized the profitability of maritime commerce, to what extent might the cumulative weight of “incremental changes” have produced growth (15)? The overall impression is that small innovations yielded some measure of economic gain among certain merchants, but this growth was probably neither sustained nor necessarily even perceptible in the short run. Nonetheless, if later Hellenistic and earlier Roman maritime economic productivity saw even a gentle growth curve—on the scale of what Saller has reasonably suggested (“Framing the Debate over Growth in the Ancient Economy,” in J.G. Manning and I. Morris, eds., The Ancient Economy: Evidence and Models [Stanford, Calif. 2005])—then seafaring technology could have returned a long-term dividend that was significant by preindustrial standards. It is hard to believe that there is no relationship between the maritime boom suggested by studies of shipwreck numbers and the concentration of innovations around the first centuries B.C.E. and C.E., even if these technologies would have had little impact on a maritime world lacking the Roman state’s stability and security.

Quantifying these factors will require continued attention to the chronologies of maritime technologies and their specific utilization or rejection among different groups and in different circumstances. Regardless of whether an innovation was universally adopted, if it gave some merchant mariners a wider range of choices in solving technical problems, then its economic impact may have been more substantial than straightforward cost-benefit analysis might predict (e.g., a vessel’s added cost vs. increased speed). With sufficient attention to detail and context, intensive programs of comparative and experimental modeling could reveal specific figures for individual vessel types, their lading and sailing capabilities, their investment and maintenance costs, and the like. Will we ever be able to distinguish one maritime innovation’s economic impact from another, or measure smaller geographical or chronological contours of change? If scholars of maritime technology and the ancient economy invest in this common goal by following the significant steps taken in this well-considered and well-structured (not to mention well-edited) volume, their efforts, too, will surely yield long-term gains.

Justin Leidwanger
Aegean Material Culture Lab
University of Toronto
Toronto, Ontario M5S 2G2
Canada
jleidwa@stanford.edu