CHAPTER THREE
3. Tracing the movement of builders to Rome
There is both epigraphic and archaeological evidence that this centripetal migration to Rome in the third century involved those specialized in construction, and that these workers ended up in the public building industry. One such example is an inscription naming two workmen of a late third century date found on the northeastern
505 Salmon 1969: 59.
506 For example, in effective medicine to fight malaria. 507 Scheidel 2003.
508 The formula for population change is P
1 = P0 + Natural Increase(Birth rate-Death rate) + Net Migration (Immigration – Emigration).
509 Jongman believes this gap was made up by the growth of the slave population, 2003: 109, 116-22.
Contra Morley 1996: 46 suggests that the ultimate incline to a population of 1,000,000 under Augustus was indicative that a sudden influx of slaves after a successful campaign would have been insufficient in and of itself to account for such an increase; he proposed 7000 free transfers to Rome annually.
slope of the Palatine.510 The inscription is on a structure excavated by Pietro Rosa, who misidentified it as the Temple of Jupiter Stator, and it was recorded as such by Christian Hülsen in CIL VI.511 While this identification would securely date the blocks along with the temple’s foundation to the first decade of the third century, photographs in the
Archivio di Stato di Roma published by Claudia Cecamore confirm that the structure was not the foundation of a temple but, rather, belongs to an as yet unidentifiable drainage or cistern structure (fig. 3.3).512 Written on the face of two blocks set at a right angle are the names:
PILOCRATE DIOCLE
The names are on the lowest course of structure’s interior, and nothing is inscribed on the courses above: they seem to be signatures. Because they are inscribed into two adjoining blocks, but at such a low and difficult point to reach, they were carved into the stones
510 Since the inscription can no longer be dated by its association with the Temple of Jupiter Stator (see below), it is given a more general date in line with the letter forms and the material (tufo giallo della via Tiberina) on which it is found.
511 Rosa’s excavations: Tomei 1993. Hülsen in CIL VI 36615.
512 2002: 75-77, fig. 26. She follows Middleton 1879: 169, “These inscribed blocks have been wrongly supposed to be part of the foundations of a temple, but their size, shape, and position show that they belong to a separate structure, and were simply part of a down-shaft, possibly to carry surface rain water into the sewer below.” The sewer, which Middleton proposes here, is reportedly brick and so not to be associated with the earlier tuff structure, which may have been part of a cistern of some sort. The Middle Republican
Figure 3.3. Archival photograph of De Rosa's excavation on the Clivus Palatinus. The inscription is visible on the lower facing blocks of the channel. Cecamore 2002 fig. 26.
sometime during the construction process, after this course of stone had been laid but before other courses made access difficult. The signers must have been involved in the construction project. It is thus interesting that the names are Greek but written in Latin: these two workers seem to have immigrated to Rome but settled there long enough to pick up the local alphabet.513 This is exactly the sort of movement I have been describing of workers traveling towards Rome in response to demand for construction labor. Their status remains at issue: both men lack the Roman tria nomina, but they also do not identify as servi as many servile artisan signatures do from this period.514 We should not
513 This inscription predates or at least is contemporary to the earliest Latin inscription in Sicily, which may be the milestone of C. Aurelius L.f. Cotta cos. 252 and 248 from Agrigento, AE 1957 158, see Reynolds 1960: 206-7.
exclude the possibility that they were incolae, resident aliens who must have accounted for some portion of Rome’s urban population.515
The archaeology of the buildings themselves is also revealing especially as it relates to the changing technology of lifting machines. As I mentioned earlier in my discussion of the Roman circuit wall (Ch. 2), holes for ferrei forfices (lifting tongs) appear disposed on both the tops and bottoms of blocks in situ in the fourth century wall, and this suggests that cranes were only used at that point in tandem with ramps, the former probably employed for unloading material off boats at the Tiber port, the latter for the actual placement of stones on building sites.516 This disposition of lifting tong holes is seen in podium blocks of the early third century Temple C at Largo Argentina, dated to the late fourth or early third century.517 This suggests that cranes using ferrei forfices were still not employed at construction sites, and that this technology remained restricted to the river port. The blocks were then maneuvered around the city by means of sleds or rollers, and workmen placed them into the foundations of Temple C on earthen ramps.
Cranes appear with regularity for the first time by the end of the third century in the interior podium courses of one of the twin temples at San Omobono. These walls relate to the reconstruction of the temples following the fire there in 213 (Liv. 25.7.6). For the first time in evidence at Rome, every block of tufo rosso a scorie nere has a regularly positioned hole for the insertion of a ferreus forfex (fig. 3.4).518 It is noteworthy that the same material was used in the foundation courses of the Temple of Juno Moneta
515Dig. 50.16.239 equates incolae with the Greek paroi/koi; discussion of Capuan incolae at p. 171. 516 Pp. 63-65.
517 Marchetti-Longhi 1960: tb. 6, pl. 1; date given by Coarelli 1981: 15.
518 The holes are found at equal spots on the reverse side of each block, but the interior is better preserved, and is thus illustrated here.
on the Capitoline a century earlier, but in that case there is no evidence that lifting machines of any kind were employed.519
This important technological shift shows the developing complexity and
permanence of the building industry in third century Rome. Rope and iron were needed in quantity, and the wood required for such cranes was not insubstantial.520 New material resources may have played a role in this expansion of technology, for example, the Roman acquisition of Bruttium after 282 B.C. expanded its timber production beyond the
local Alban hills.521 A few permanent cranes at Rome’s loading docks were one thing,
Figure 3.4: Plan of the interior face of the cella wall of the western San Omobono temple. A schematic at the top right locates the wall. Each block on the lower course shows a regularly positioned hole for a lifting tong; the
upper course is too eroded to show similar evidence.
519 See discussion at pp. 66-69.
520 From a later period, part of Domenico Fontana’s payment for lifting the Vatican obelisk was the right to keep the wood from the lifting machine after the project. In our period, wooden siege engines were kept as spoils of war (e.g. Liv. 25.40.3), showing the importance of the material itself and the difficulty in reverse engineering examples.
but the movement of a crane or its component parts to various worksites, the planning and setting-up at the worksite, and the operation of the machines were all specialized tasks requiring advanced technical knowledge. Evidence of their consistent use entails innovation, but it also entails a change in the workforce with a higher ratio of skilled to unskilled workers as opposed to the masses of unskilled workers necessary for portage and for pushing and pulling material up ramps.522
The newfound ubiquity of the crane may indicate the discovery at Rome of compound pulleys, which doubled the crane’s mechanical advantage and made it more useful for lifting heavier loads. The fact that this change first appears in the San
Omobono temples may also point to the presence of Syracusan builders at Rome during this time. The sanctuary at San Omobono burned in 213; in the following year,
Marcellus conquered Syracuse. He celebrated an ovatio at Rome in 211, and paraded through the city streets with his spoils; among them were the war machines created by Archimedes to defend Syracuse against Roman siege.523 Depending on where we see the
Porta Triumphalis, we may even imagine Marcellus carrying these novel war machines directly past the ongoing construction of these two temples, although this is hardly necessary to infer the transfer and diffusion of technology.524
War engines and building machines formed part of the larger class of machinae in antiquity and relied on closely allied technologies.525 Associated with many siege
522 This was a change in the labor-force ratio: unskilled labor was never completely phased out: see Hor.
Ep. 2.2.72-73.
523Catapultae ballistaeque et alia omnia instrumenta belli lata (Liv. 26.21.7).
524 The Porta Triumphalis is on Coarelli’s account northwest of the San Omobono temples (1988: 372; cf. Haselberger in Haselberger et al. 2002, “Porta Triumphalis”); contra Wiseman 2008b: 391 who is less confident that it can be placed at all.
525 As is clearly the case with Vitruvius’ tenth book on machines including both construction cranes and war engines.
engines was the compound pulley, which doubled the mechanical advantage of lifting machines and with whose invention ancient authors credited the Syracusan
Archimedes.526 Vitruvius knew of the compound pulley (rechamus); he also knew of Archimedes’ treatise on machines.527 Treating Vitruvius as a terminus ante quem, scholars have not known with more precision when the compound pulley debuted at Rome. However, the development of lifting technology visible in the temples from the time of Marcellus, which I have identified, may represent the original transfer of Archimedean lifting technology to Rome in the late third century.
This hypothesis is important because technological innovation can indicate population movement. This innovation and the subsequent operation of complex lifting engines imply a skill-set that was not previously evinced at Rome and would have required skilled workers. Again, gleaning the status of these skilled workers who helped with the technological transfer is difficult. These workmen may have been slaves, part of the same spoils of conquest as Archimedes’ machines. As such, their decision to bring their specialized crafts to Rome had little to do with market-driven choice. On the other hand, Temin and other economists have often argued that innovation is a hallmark of free
526 Plut. Marc. 14.8 and several late antique sources discussed by Wilson 2008: 343-4. But Wilson notes that the historical fact of this point is problematized by the fact that the pseudo-Aristotelian Mechanica
seems to describe the device a century prior.
527Rechamus: 10.2.1; Archimedes on machines 7.pr.14; Vitruvius again specifically cites a treatise by Archimedes at 1.1.16. This is all very interesting as, according to Plut. Marc. 17.3-4, there was another ancient tradition that Archimedes intentionally abstained from committing any of his technological innovations to writing, see also Wilson 2002a: 4. If, however, on my suggestion the compound pulley entered Roman engineering via Archimedes and Syracuse, this explains the development of the ancient tradition associating him with such an innovation.
labor: the incentive-laden pressure of a market encourage higher efficiency and better technology.528