ANCIENT OMPHALOS AT DELPHI: GEOMETRICALLY A SPACE‐INVERTING ANAMORPHOSCOPE

Whether the artisan who made the Omphalos at Delphi over 2500 years ago recognized the optical transform properties of its shape or not, its geometrical features are nevertheless those of a space‐inverting anamorphoscopic mirror. Specifically, it is similar in shape to a circle‐inverting anamorphoscope. We speculate that select members of the ancient religious sect at the Temple of Apollo at Delphi realized the symbolism of inverting all of space outside the Omphalos into the image field inside its base, thus making it the virtual centre of the World.     

BUILDING MATERIALS OF THE THEATRE OF MARCELLUS,ROME*

The building materials of the Theatre of Marcellus, 44–11 bce , reflect Roman builders' careful selections of tuff and travertine for dimension stone and volcanic aggregates for pozzolanic concretes. The vitric–lithic–crystal Tufo Lionato tuff dimension stone contains a high proportion of lava lithic fragments, which increase its compressive strength and decrease water sorption, enhancing durability. Sophisticated installations of travertine dimension stone reinforce the tuff masonry, which is integrated with durable concrete walls and barrel vaults. The pozzolanic mortars of the concretes contain harenae fossiciae mainly from the intermediate alteration facies of the mid‐Pleistocene, scoriaceous Pozzolane Rosse pyroclastic flow. They have pervasive interpenetrating pozzolanic cements, including strätlingite, similar to high‐quality, imperial era mortars. Concrete walls are faced with refined Tufo Lionato opus reticulatum and tufelli, and opus testaceum of fired, greyish‐yellow brick. The exploratory concrete masonry, which includes some of the earliest examples of brick facings and strätlingite cements in Rome, and the integration of these materials in complex architectural elements and internal spaces, reflect the highly skilled workmanship, rigorous work‐site management and technical supervision of Roman builders trained in republican era methods and materials.     

A Methodological Approach Towards Conservation

Abstract

Since conservation became a recognized discipline, professionals involved in conservation projects have tried to find the best criteria for their interventions. Often these criteria remain quite vague, based on the idea that every historic building has its own special conditions, which make its problems different from other buildings. This conviction, which is appropriate at one level, has serious consequences due to the lack of a consistent methodology. More than a lack of criteria, we might talk about a lack of 'habit' in identifying values in the Mediterranean region: the concept of values is much more widespread in Anglo-Saxon countries.

If we take a look at the history of conservation, there are a number of cases which are often used as models: for example, the Colosseum or the Arch of Titus in Rome, both interventions which are greatly admired and included in many conservation manuals. More recently there are projects which are widely accepted by the heritage conservation community as well: the paper explores the Palace of the Partal (Granada), the Villa Romana del Casale (Piazza Armerina), the theatre at Orange, and the Insula Orientalis I in Herculaneum. In this article, I suggest that there are constant elements within these conservation projects, reflecting typological, structural, constructional, functional, aesthetic, formal, historical, and symbolic values. These features represent a way of planning a conservation project and a critical methodology to judge the outcomes of the project in an objective manner. The methodology is qualitative rather than quantitative. All historic buildings have a set of values developed from their origins and throughout their history. These values can be analysed to extract the most important elements to be preserved. Analysing the values of our built heritage will allow us to create better decision-making processes.     

DNA AND PROTEIN RECOVERY FROM WASHED EXPERIMENTAL STONE TOOLS*

Traces of protein and DNA are preserved on stone tools used to process animals. Previous research documents the identification of protein residues from tools sonicated in 5% ammonium hydroxide, but it remains untested whether the same treatment yields useable DNA. In this study we report both DNA and protein recovery using 5% ammonium hydroxide from residues on stone tools. We extracted 13‐year‐old residues from experimentally manufactured stone tools used to butcher a single animal. We also show that surface washing procedures typically used to curate stone tools remove only a small fraction of the DNA and protein deposited during animal butchery.     

THE CHARACTERIZATION OF PAINTS AND WATERPROOFING MATERIALS FROM THE SHIPWRECKS FOUND AT THE ARCHAEOLOGICAL SITE OF THE ETRUSCAN AND ROMAN HARBOUR OF PISA (ITALY)*

This work presents the results of a diagnostic survey on the shipwrecks from the archaeological site of the ancient harbour of San Rossore (Pisa, Italy). The original waterproofing, caulking and painting materials were characterized by Fourier transform infrared spectroscopy (FTIR), gas chromatography – mass spectrometry (GC–MS), energy‐dispersive X‐ray microanalysis (EDX) and X‐ray diffraction (XRD). The major constituents of the waterproofing and caulking materials detected on the planks were tricyclic abietanes showing a high degree of aromatization. These compounds are indicative of a pitch obtained from the wood of trees of the Pinaceae family. The analysis of the organic components of the paint samples revealed diterpenoid acids characteristic of Pinaceae resins together with linear long‐chain alcohols and fatty acids, highlighting the presence of beeswax. Noticeably, the characteristic odd carbon number alkanes that are normally present in beeswax were not detected. The EDX and XRD analyses showed that hematite, calcite, cerussite and kaolinite were employed as pigments to paint the ships’ hulls.     

The Determination of Lead Isotope Ratios by Multiple Collector Icp‐Ms: A Case Study of Early Bronze Age Artefacts and their Possible Relation With Ore Deposits of the Erzgebirge*

Lead isotope analyses of Early Bronze Age metal artefacts from the Aunjetitz (Ún?tice) culture in central Germany and Bohemia were determined in order to find out whether they could be related to ore sources of the Erzgebirge. Historical mining began only in the 12th century ad , but despite the lack of convincing field evidence it has frequently been suspected that this region was already being exploited in prehistoric times. For the determination of the lead isotope ratios, the new technique of multiple collector inductively coupled plasma mass spectrometry (MC‐ICP‐MS) was employed, which combines relatively easy sample preparation with highly precise and accurate measurements. The results show that there is still no evidence for prehistoric mining in the Erzgebirge, but the Rammelsberg deposit in the Harz Mountains might have supplied some of the copper. Mining of stream tin in the Erzgebirge remains a possibility, but no positive evidence can be extracted from the data.     

MAGNETIC SUSCEPTIBILITY VARIATIONS AT MONS CLAUDIANUS AND IN ROMAN COLUMNS: A METHOD OF PROVENANCING TO WITHIN A SINGLE QUARRY

Mons Claudianus in the Eastern Desert of Egypt was an important source of granodiorite for Roman columns. Computer contouring of 1119 magnetic susceptibility measurements at the quarry shows systematic variations, with low readings in the west of the quarry area and higher readings in the east. One hundred and seventy measurements on 62 columns of Mons Claudianus type in Rome and its environs were compared with the quarry readings, using a t-test based procedure. Some columns with distinctively low or high magnetic susceptibility could be provenanced very precisely to areas of about 700 × 700m within the 9km² of Mons Claudianus. Columns with susceptibility in the middle of the Mons Claudianus range could not be provenanced precisely. Results indicate early (first century AD) use of both west and east parts of Mons Claudianus, and contemporaneous use of several parts of the quarry, rather than systematic or sequential opening of the area. Columns found in third-century AD monuments, provenanced to the same parts of Mons Claudianus as earlier material, may indicate reuse of columns in some monuments. Magnetic susceptibility constitutes a portable and non-destructive method capable of provenancing not only to a quarry, but to specific areas within a single quarry.     

THE ‘FRYING PANS’ OF THE EARLY BRONZE AGE AEGEAN: AN EXPERIMENTAL APPROACH TO THEIR POSSIBLE USE AS LIQUID MIRRORS*

The so‐called ‘frying pans’ are peculiar vessels, most of them made of terracotta, flat and shallow, usually decorated on the outside part and dated to the Early Bronze Age. They were unearthed mostly in the Cyclades, in Crete and on the Helladic mainland. There are also a few artefacts made of stone and of bronze, from the Cyclades and Asia Minor, respectively. The intended purpose of these objects is disputed. Several interpretations exist for their function, the earliest one being that of liquid mirror vessels. We investigated the mirror hypothesis experimentally, by testing trays with attributes similar to those of the original ‘frying pans’, filled with a series of liquids familiar to the people of the time and the place where those vessels were made. The criterion employed was the contrast of mirror images. We conclude that, provided that some minimal prerequisites are met, the ‘frying pans’ are quite appropriate as liquid mirror vessels.     

‘GRANITO DEL FORO’ AND ‘GRANITO DI NICOTERA’: PETROGRAPHIC FEATURES AND ARCHAEOMETRIC PROBLEMS OWING TO SIMILAR APPEARANCE

Granitoid rocks were among the stone materials most frequently used for columns and pillars during the Roman period. When employed in Rome and the Mediterranean provinces, they were mainly quarried in Egypt, in Asia Minor and in Italy. Some of these rocks show very similar macroscopic features, so it is often very difficult to tell them apart with the naked eye. This is the case with the ‘Granito del Foro’ (or Marmor Claudianum), from the Gebel Fatireh, in the Eastern Desert, and the ‘Granito di Nicotera’ (Calabria), both exploited from the first century ad onwards. Both feature medium grain size and a white‐greyish colour with black patches. In order to obtain a certain microscopic and geochemical discrimination of these rocks, and to provide the first known petrographic classification of the ‘Granito di Nicotera’, a comprehensive mineralogical, petrographic and geochemical investigation was performed on several samples from the quarry. The results were compared with the corresponding data known for Marmor Claudianum in the literature. Good discrimination between the granites is possible, mainly on the basis of modal mineralogy and geochemical characteristics. The ‘Granito del Foro’ contains hornblende, while the ‘Granito di Nicotera’ contains muscovite, and has a distinctive peraluminous index and trace element abundances.     

X-RAY MICROANALYSIS OF ANCIENT GLASSY MATERIALS: A COMPARATIVE STUDY OF WAVELENGTH DISPERSIVE AND ENERGY DISPERSIVE TECHNIQUES*

Sensitivity, precision and accuracy of quantitative microanalysis of major, minor and trace elements present in ancient glasses by energy dispersive spectrometry (EDS) is compared to that by wavelength dispersive spectrometry (WDS). Although there are certain problems with EDS due to peak overlaps and background noise, the precision and minimum detection limits of EDS for most of the important elements in ancient glasses were found to compare favourably to those of WDS. Both EDS and WDS, when quantified by comparison to glass standards, can produce reliable results which are adequate for most technological questions.