ESTABLECIMIENTO DE UN SISTEMA DE DOCUMENTACIÓN Y REGISTRO.´

vaults, as well as for church furnishings such as choir screens, railings, doors and benches. Finally, it is likely that some private housing relied more extensively on timber. Because, once again, archaeologists and restorers have failed to take note o f the evidence which may have come down to us from the early middle ages, we are forced to rely on textual evidence - and if this is not wholly satisfactory even for church beams, it is still less so for subsidiary uses.

Much o f the wood required for small-scale building projects and furnishings could be found nearer to hand. Renaissance projects such as ship-building and the construction o f mechanical devices cited by Meiggs took their timber from forests as near as Praeneste, Anzio and the Via Laurentina (1982, 382fï). The supplies brought in by the popes discus­ sed above were also adapted for other purposes in Rome, as Gregory I himself states (Reg. IX, 175; some he also exported to Alexandria for ship-building). Surviving archi­ traves at S. Croce are o f chestnut, like the beams (Colini, 1955, 156). The imported fir served for the basilicas' coffering as well as the beams (CC 65, above); again, it probably found other uses, such as the house "modo edificata abetis" near S. Maria in Via men­ tioned in a document o f 1042 (Hartmann, 1895-01 I, 97). However, wood was not so abundant that high-quality timber could be afforded for such things as scaffolding, as the irregularly-spaced and sized putlog holes in most early medieval church walls testify (cf. the "dangerously-spaced" holes at Leo Ill's SS. Nereo & Achilleo and Sergius II's S. Martino ai Monti, which utilised small round saplings - CBCR III, 110 & 143). Even during the fourteenth-century replacement o f S. Peter's roof, the decayed Constantinian beams were sawn up and re-used for planks to clad the rafters (Cerrati, 1915, 85). As one would expect in any era, left-over stock was saved for later use: the same project relied on old timbers stored at the Lateran (op. cit. 99), and off-cuts o f cypress and chestnut from a workshop at S. Peter's were used during the twelfth century to prepare a rough frame for the ninth-century bishop's chair (Cagiano de Azavedo, 1972, 253).

2.2 Metal

With the exception o f a number o f lead aqueduct pipes there is a dearth o f ar­ chaeological evidence for the architectural use o f metal in early medieval Rome. Again, the bulk o f evidence must come from textual sources, supplemented by examples from outside our area or timespan.

The chief use o f metal in building was for roofing. Lead sheeting would serve, as it has done until recently, as a damp-proofing between the ro o f timbers and tiles, especially in vulnerable areas such as the valleys between the folds o f the transept and nave o f basilicas. It must have been for such a purpose that Gregory I agreed to pay for 15001bs o f lead to repair monastery buildings on an island in the Gulf o f Gaeta (Reg. I, 48). During the second phase o f Hadrian I's repair o f the ro o f o f S. Peter in 786 the pope reminded Charlemagne to send the arranged 20001bs o f "stagni", suggesting that a further lOOlbs be requisitioned from each count o f Italy (CC 78). "Stagni" here might mean either tin or white lead. Tin would have been a viable material for damp-proofing, but highly unusual in view o f its rarity; it is more likely that lead was intended. A depiction o f just such a use o f the material seems to be intended in an eleventh-century drawing o f S. Peter's, where lead flashing is seen beneath the tiles in the valleys o f the quadriporticus (Picard, 1974, 871).

Domes might be entirely covered with lead sheets; the only references to the use o f lead for roofing in the Liber Pontificalis concern the rotundas o f SS. Cosma & Damiano, repaired by Sergius I, and the Pantheon, whose dome was sheathed in "chartis plumbeius" by Gregory III (LXXXVI, 13; XCII, 12). Such lead roofing sheets have been found in contemporary Ravenna at the basilica Ursiana, bearing the stamps o f bishops Theodore (677-8) and John VII (723-32), and in Rome from the later middle ages and Renaissance (Stevenson, 1888, 442ff).

Perhaps the best-known use o f lead in Roman times was for the conduit pipes o f aqueducts. This continued in the early middle ages, and from the earlier part o f our period

there are several examples o f stamped fistulae; that bearing the name o f Basilius Decius, found on the Aventine near S. Alessio (CIL XV.2, 7420, assigned to the Decius o f Var. II, 32-3); one mentioning a consul o f 471, found at the cathedral o f Portus (Bull. Comm. 1878, 132ff); and a number from S. Lorenzo fuori le Mura, all with the inscription: "salvo papa lohanne / Stefanis pp reparavit", assigned to pope John I on the basis o f the praepo- situs Stefanis’ appearance in another inscription o f 526 (Marucchi, 1902). Other, less- precisely dated, inscribed fistulae from Rome include tw o which name their respective religious establishments (a "hospetalis S. Crisogoni" and an unidentified xenodochia- CIL XV.2, 7257-8) and one bearing a chi-rho, manufactured by an "ofRcina agnelli" (Bull. Comm. 1878, 136). O f the many notices in the Liber Pontificalis o f papal repairs o f aqueducts, that regarding Hadrian I’s work on the Aqua Traiana refers specifically to the pontiff "adding a great amount o f lead" so that the conduit leading to S. Peter’s atrium might function once more (XCVII, 59).

Copper served for guttering, as at S. Martino ai Monti where Crostorosa believed it survived until 1891; during the same restoration he spoke o f the original iron ties used for reinforcing the roof-truss joints (1897, 202). There is a unique reference in the Liber Pontificalis to a reinforcement o f the apse o f SS. Apostoli by Hadrian I with iron bars (cancalis ferreis - XCVII, 50); the sockets for similar metal tie-beams survive in the columns o f S. Sabina, here used to stabilise the nave colonnades (Wilcox, 1981, 49). The Liber Pontificalis also makes constant reference to the adornment o f churches and palaces with "cancellos" o f bronze, which must refer to metal barriers, gates and railings, often part o f the liturgical furnishings, and as much ornamental as utilitarian (cf. the sixth- century openwork bronze window-frame from the crypt o f S. Apollinare in Classe, which replicates the shield m otif seen on so many contemporary marble choir-screens - lacobini, 1990, 76 & fig. 12). Monumental doors o f bronze were similarly prized. Lastly, although they have not survived nor been referred to in texts, nails would have been needed in great quantities, as well as similar fastenings for roof tiles (Picard’s eleventh-century illustration o f S. Peter’s quadriporticus seems to show the tiles held with metal hooks - 1974, 871). Decorative marble sheets and the panels o f choir screens were also fixed with metal

cramps and dowels: often the only evidence is holes left in the masonry - as in the arcades o f S. Sisto Vecchio - but, in the base o f John VIFs ambo at S. Maria Antiqua, the original lead dowels were preserved (Apollonj-Ghetti et al, 1944-5, 248; Rushforth, 1902, 90).

Having established the evidence for the architectural use o f metal we should now consider its supply. Davies (1935, 63ft) has listed the areas in Italy where gold, silver, tin, lead, copper and iron were mined during the Etruscan and Roman periods, and there is no reason why it should have proved impossible for people o f the early middle ages to continue the practice. However, given the complete silence o f all the sources on the

4

subject , and more importantly given the substantial notices o f the re-cycling o f metals in the period, it is almost certain that all architectural use o f metal in Rome relied on spolia. Lead had been mined on Sardinia at least up to the fifth century, but we hear nothing from Gregory I on the subject, although he was greatly concerned with affairs on the island and organised various building projects there (Davies op. cit. 69; Reg. IV, 8-10). When he arranged for the replacement o f lead in monastery buildings on the Eumorphian Island in the Gulf o f Gaeta, he had it collected in Campania - where there are no natural lead deposits; the material here was obviously spolia. In addition to re-casting lead and bronze and re-forging iron, certain metal objects could be used again directly, with no re-working: the bronze ro o f tiles moved by Honorius I from the Temple o f Venus and Rome to S. Peter's, or the "great bronze decorated doors o f wondrous size" transported from Perugia to the quadriporticus o f S. Peter's by Hadrian I (LP LXXII, 2; XCVII, 96).

The theft o f architectural metal and bronze statues for scrap is well-attested. Under Theoderic it was thought necessary to assign two functionaries - the Architectus Publicor- um and the Comitiva Romana - simply to prevent the theft o f the city's statues (Var. VII, 15 & 13). In exhorting the latter to be always vigilant, Cassiodorus clearly has in mind the danger to bronzes: "nor are the statues absolutely dumb; the ringing sound which they give forth under the thief seems to admonish their drowsy guardian." We have seen that the

4 I know of no later reference than Athalaric's suggestion that a "chartarius" be sent to Bruttium to look into the possibility of extracting gold from the Rusticiana estate - Var. IX, 3.

official concession-formula for abandoned public monuments retained the rights over any precious materials for the state: bronze and lead are mentioned specifically (Var. VII, 44). Elsewhere the Variae record the continued theft o f metals from standing public buildings, notably aqueducts (III, 31). Such "removals" were endemic throughout the early middle ages: Honorius I obtained permission from Heraclius for his spoliation o f tiles from the Temple o f Venus and Rome, but it seems unlikely that the average craftsman or scrap merchant followed any official procedure; certainly the emperor Constans II set a bad precedent during his twelve-day campaign to remove "all the city's bronze decorations" (LP LXXVIII, 3). By the time o f Hadrian I's repair o f the Aqua Traiana, thieves had removed all the lead piping o f the branch line to S. Peter's, leaving only the damaged portions (LP XCVII, 59).

The few surviving examples o f new-made architectural metal objects - Hilarius I's inscribed bronze doors at the Lateran Baptistery, the stamped fistulae from Rome, the lead tiles from Ravenna - must presumably have been re-cast from such stolen scrap, although there is no certain proof in our period (lacobini believes that the only new elements o f Hilarius' doors were the actual inscription and the embossed crosses, beaten-on in copper and silver respectively - 1990, 73). The terminology in the Liber Pontificalis (fusis, fabre- factum) would suit both new casting and re-casting; references to Leo I's replacement o f looted silverware with "conflatas hydrias", however, would suggest a re-working o f metal on a smaller scale (XLVII, 6; cf. Delogu's observations on the melting-down o f offerings to provide new church vessels - 1988b, 277). Later, during the 1337 re-roofing o f S. Peter's, the account-books speak precisely o f Roman workmen re-casting the lead damp- proofing from the old sheets (Cerrati, 1915, 90).

Archaeological evidence for metal-working in early medieval Rome is sparse. The most recent published material from the excavations at the Crypta Balbi reports the discovery o f two pit furnaces bearing traces o f the fusion o f copper and bronze, perhaps dating to the eighth century (Sagui, 1993, 132; these might be placed in connection with nearby strata o f metal refuse o f similar date-range - AM 1993, 415). The remains o f small

medieval structures built up against the north end o f the Basilica Julia have yielded strata reflecting "attivita' di tipo artigianale”, including an assemblage o f despoiled metal ties (Maetzke, 1991, 84-5). The assumption that this, too, represents the traces o f metal­ working relating to the re-casting o f scrap is tempting, but in the absence o f any furnaces we cannot be sure; elsewhere, in fact, a similar assemblage o f metal cramps has been taken to denote a workshop charged with restoring rather than despoiling the Forum's mon­ uments (Giuliani & Verduchi, 1987, 163). The more disparate collection o f metal objects - most o f them broken - found in "medieval" buildings destroyed during the construction o f the Piazza Vittorio quarter would be a better example o f a possible scrap-metal merchant's workshop (NS 1888, 132; Bull. Comm. 1888, 76).

2.3 Stone

Unlike the materials considered up to now, tufa and marble have survived in great quantities in early medieval churches and fortifications in Rome. We can therefore concern ourselves here chiefly with a discussion o f their source and supply as opposed to making a case for their use. Together with brick and mortar they served for the foundations and load-bearing walls o f all monumental architecture; regarding even those domestic struc­ tures noted in the tenth-century Roman property documents (and from the seventh and eighth centuries in Ravenna), it seems that stairs and paved courtyards were commonly o f marble, with the superstructure at least based around "pilae tiburtinae", or tufa piers (Hubert, 1990, 215ff).

2.3.1 Tufa

The question as to whether tufa was newly-quarried during the early middle ages in Rome remains unanswered. As with metals, there is no physical or textual evidence for quarrying, but much for the use o f spolia. The only secure proof for continued quarrying

would be the discovery o f datable material in a shaft or at a rock-face; in the absence o f this we are reduced to supposition. The ready availability o f tufa in Rome is well-known. Despite the emphasis given to those quarries and types o f tufa located outside the city, there is a great variety o f the stone occurring naturally almost everywhere within Rome itself; this was exploited throughout the Classical period far more than has been generally noted (Blake I, 39; DeLaine, 1992, 130). Such availability, together with the stone's ease o f working, would have made continued quarrying into the middle ages a simple matter. However, our earliest reference to what may be quarrymen comes in an eleventh-century property document, and the first likely use o f freshly-quarried tufa - identified as such due to the homogeneity o f the small rectangular blocks, or tufelli - seems to have been in Honorius Ill's S. Lorenzo fuori le Mura around 1200 (Hubert, 1990, 224; Avagnina et al, 1976-7, 236). Prior to this date, the examples o f tufelli found in medieval buildings show the same characteristics o f re-use as do the bricks: they are o f unequal size, o f varying colour, often broken, and with rounded comers - all signs that they were removed from various earlier buildings (Heres, 1982, 30). In a few cases the blocks' very regularity o f size, and their precise square shape, suggest that Roman walls o f opus reticulatum were the spolia source (CBCR I, 311; III, 169).

When we find rising walls o f spolia tufelli, they are used in conjunction with spolia brick in a technique now commonly known as opus vittatum - alternating courses o f brick and tufa^. Since tufa is an inferior building material to brick, being structurally weaker, less durable, less resistant to fire and damp, and generally less plastic to work with, we are faced with the question o f why it was used at all. Various reasons have been suggested, from its low cost (Barclay-Lloyd, 1985, 243), to a shortage o f brick (Apollonj-Ghetti et al, 1944-5, 228), to decorative taste (Pani-Ermini, 1987, 20). The last idea would seem impossible to prove at this stage (it is in fact possible that all walls were originally ren­ dered with stucco or plaster). The first two seem reasonable, but inspire further questions: why, since we are dealing with materials which were all spolia anyway, would it have been more expensive to remove bricks from older buildings than tufa? And given the vast