- Vitruvius and the Limits of Proportion1
I come to the present topic with some trepidation. Unlike many of the contributors to this volume, I am not a Vitruvian scholar, nor does my main interest—even in this paper—lie with Vitruvius himself as such. Rather, I wish to consider the (exceptionally rich) evidence he provides for some more general questions of Roman metrology. This inquiry does not have to do with antiquarian questions of the “correct” modern equivalents for various Roman measurements; I suspect those questions are ultimately unanswerable and even incoherent for reasons beyond the scope of this paper. I ask, instead, what styles or modes of measurement were available to the Romans and what considerations dictated their use in particular contexts. This is a question I address more broadly elsewhere, but Vitruvius’s text proves so metrologically rich that it deserves to be treated on its own.
De Architectura is, of course, one of the Roman texts densest in measurements, along with a number of medical and agricultural works and the writings of Frontinus and the Elder Pliny. Even among the works just mentioned, it stands out both for the way measurement is crucial to the tasks at hand (a Natural History could be written without measurements) and for how measurement is explicitly thematized (Scribonius Largus has only two sentences on the measures he uses in his drug recipes). Vitruvius is presumably a product of the metrological culture he is embedded in, just as any author is a product of his or her culture more broadly. At the same [End Page 281] time, he occupies a unique position and trajectory within that culture, again just like any other author. So what I want to consider here is precisely how he reflects and inflects the metrology of his day.
The most obvious starting point for such an investigation is probably the Vitruvian feature best known outside professional classics: the role of proportion in de Architectura. Some of this contemporary reputation derives from the even greater fame of Leonardo’s later illustration of the so-called Vitruvian Man, based on 3.1.2:
For the human body is so designed by nature that the face, from the chin to the top of the forehead and the lowest roots of the hair, is a tenth part of the whole height; the open hand from the wrist to the tip of the middle finger is just the same; the head from the chin to the crown is an eighth, and with the neck and shoulder from the top of the breast to the lowest roots of the hair is a sixth; from the middle of the breast to the summit of the crown is a fourth.2
But proportion is much more prevalent in Vitruvius than just this passage (though I will return to it a couple of times for further comment). He uses proportions for measurement in numerous places, many involving multiple instances each (3.2.5, 6; 3.2, 4, 6, 7, 10–11; 4.1, 3; 5.1–3, 5–7, 9–13. 4.1.1, 6–8, 11–12; 3.2–8; 4.1; 6.1–6; 7.1–5; 8.1–3. 5.1.2–5; 6.5–6; 9.2-4; 10.4–5; 11.2; 12.2–3. 6.3.3–8; 8.6–7. 7.1.3, 5. 8.6.14. 9 pref. 8; 7.1). Moreover, those proportions are used in a variety of contexts. Beyond the most famous cases of the human body and the various architectural orders, for instance, there are the proportional features of theaters, baths, and harbors; the designs of foundations and staircases; and the sundial. Perhaps most significant, however, is the thematization of proportion. Symmetria, the formal, mathematical correspondence of the various elements of the whole (1.2.4), is one of Vitruvius’s six basic design principles (1.2.1), and, in fact, the most commonly mentioned of the set (eighty-four times; Wilson Jones 2000.40). Mentions of proportio add almost half again as many mentions. And the [End Page 282] proportional account of the human body itself is not a random piece...