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Historic shipwrecks frequently contain a large proportion of wrought-iron tools, fasteners, and other types of artefacts. Encrustations readily form around such objects in many marine environments. Depending on many factors, the iron objects inside these encrustations may be well preserved, completely disintegrated, or poorly preserved but still present. The latter type of encrustation is every conservator's nightmare because removing the encrustation yields merely a poorly preserved artefact still in need of extensive additional conservation. Neatly separating the artefact from its encrustation in order to obtain a natural mould for casting is generally impossible. Having encountered this problem many times, the authors began to experiment with the extraction of metallic iron from poorly preserved encrusted artefacts using galvanic dissolution. Data on rates of dissolution were gathered for three experimental configurations. The results of a test conducted on an encrusted artefact were promising, but inconclusive.

Electrolysis performs three useful functions for the conservator: it mechanically cleans artifact surfaces, removes salt, and (theoretically) reduces corrosion products. Because each of these functions is fundamentally different, they must be separated for study. Mechanical cleaning and the reduction of corrosion products during electrolysis are recognized as relatively minor effects; therefore, from the perspective of the archaeological conservator, the most important function is chloride removal. The authors implemented a study to discover what current density most efficiently promotes this function with respect to wrought-iron artifacts recovered from marine environments. Complete data are presented for three experiments performed on archaeological specimens in which current was controlled and the quantity of chloride removed was measured. Over the course of four experiments, the lower current density of 50μ.A. cm-2 removed an average of 4·9 times more chloride (expressed in mg.A-1hr-1) than a...

Two stories are told simultaneously: one that may have been, and one that yet might be. The story of the voyage that might have been is based on archaeological evidence provided by the earliest shipwreck discovered in the New World. These two stories are set in different eras to demonstrate certain constants in the human drive to explore the unknown, in the methods used, and in the consequences encountered.

Introduction Artefacts recovered from the sea in the late 1960s and early 1970s were re-examined in 1993 to determine their present condition, to evaluate the effectiveness of the original treatment, and to re-treat those exhibiting symptoms of active corrosion. Originally conserved by mechanical cleaning, electrolytic reduction, and coating in microcrystalline wax, after 20 years the artefacts were in good condition, but the microcrystalline wax coating was thin and no longer impermeable to air penetration. In some places, slow corrosion was taking p l a c e . M o r e t h a n 3 5 0 1 6 t h -century wrought-iron items were re-treated with the experimental tannic acid solution de-scribed below followed by a tannin-derived coating which is impervious to air and moisture.

Presentation de la methode de traitement des objets ferreux du 16e s. apr. J.-C. decouverts en milieu aquatique, consistant a proteger les objets de la corrosion, de l'air et des moisissures grâce a une solution d'acide tannique et a un revetement a base de derive de tannin

This article presents a detailed study of crossbows recovered from the shipwrecks of Padre Island, Texas, dating to 1554. Traditional archaeological and historical analysis is enhanced by production of working replicas of the light Spanish-style crossbows. A possible maritime adaptation of the weapon is identified.

The building of discovery-period ships for the specific purpose of testing the accuracy of carefully determined but hypothetical designs seems to be a more useful approach to replication than fanciful celebratory inventions. Before an experimental replica ship of any type can be built, a number of prerequisites must be met: Sufficient reliable information must be available. All avenues of research—archaeology, history, and ethnology—must be exhausted. An inventory of the technology available to the original shipwrights must be taken. This article outlines the process of replicating an early 16th-century caravel from the formation of a reliable hypothesis through the process of construction, fitting out, fine-tuning, and testing.

Historical research, geomorphological reconstruction, test excavation, and remote sensing are being applied to the search for the caravel Gallega and the outpost Santa Maria de Belen abandoned by Christopher Columbus in 1503. Comparison of modern geographical features with descriptions contained in historical documents identified Rio Belen, Panama, as the most promising locality to search. In spite of unexpected difficulties presented by the physical environment, remote sensing surveys and test excavations revealed anomalies and historical artifacts that may be associated with the target sites.

Earlier this year, a BBC television series dived into the regions where underwater archaeology fades into the murkier waters of treasure-hunting. This is an opportune moment to review an archaeologist's account of his rôle in the richest of recent recoveries, the gold from the Spanish galleon Atocha.

It has often been said that ships wrecked on coral reefs in shallow tropical water seldom preserve their archaeological integrity: that the wood of the hull is not sufficiently well-preserved to warrant study, that smaller iron artifacts invariably are in poor condition, that ballast of such wrecks has no archaeological significance, and that surviving components of these sites are frequently re-sorted and further degraded with each passing storm to the extent that artifact distributions are rendered senseless. This “conventional wisdom” that all shipwrecks are in “marine peril” and must be salvaged as soon as possible has supplied a pretext under which untold numbers of Caribbean shipwreck sites have been obliterated.Results from three seasons of excavation on a 16th-century shipwreck on Molasses Reef in the Turks and Caicos Islands, British West Indies, indicate that this loss of integrity is not always the case. Field methods for recording distributions of components within the site are describ...