Unknown substance growing on Alamo cannon removed

Modern(ish)

Texas A&M University researchers have been combatting a conservation threat on an 18th century bronze cannon that was used at the Battle of the Alamo on March 6th, 1836. An unknown white chalky substance has been growing on the surface of the bronze four-pound cannon. It has not been found on any other bronze or iron cannons at the Alamo Museum.

The cannon was in central Mexico and was then deployed to the frontier where it was used in several battles, including the 1813 Battle of Medina, the largest land battle in Texas history. At some point, perhaps during the Battle of Concepción in 1835, it was captured by Texas and brought to the Alamo. It was made in a sandcasting technique, and is unusual in its metal composition. The research team found lead and other atypical metals in the mix, and there are areas where defects in the casting and air bubbles are clearly visible. Given the foundry’s limited skills, it’s remarkable that this cannon saw decades of battlefield action and never blew itself up.

“We’ve spent the better part of a year and a half trying to work out why this substance is growing,” Dostal revealed. “It turns out, this might be a byproduct of the chemicals used in the cannon’s conservation process back in 2008 and again in 2019. The substance is a precipitate of these chemicals starting to crop up on the outside of the cannon.”

To replicate the results, Dostal and Breyfogle created their own bronze blocks with a composition resembling that of the cannon. They then applied identical methods and treatments to these blocks.

“This is a rare occurrence, and we spent a large amount of time figuring out the exact cause,” Breyfogle said.

They aren’t sure exactly what the white material is even now, but it’s a precipitate of the electrolysis process used to clean the cannon previously. Instead of cleaning it, somehow the combination of caustic chemicals in the electrolysis tank combined with the non-standard metal composition in this cannon to create carbonate blooms that are now marring the surface.

To remove the white substance and prevent it from reoccurring, researchers have enlisted another chemical, a 5% solution of formic acid and deionized water. It removed the chalky deposits without harming the bronze underneath. They applied the solution with cloths on the outside of the cannon and a tennis ball on a stick to apply it down the full length of the bore. The white substance disappears on contact, but conservators had to apply the solution in several coats over the course of months. This process was done in view of the public. Now that it is complete, the cleaned cannon is back on display at the Alamo Museum.

One hopes this chemical doesn’t suffer from the law of unintended consequences like the last one did, but ultimately the conservation team preferred to roll the dice with a dilute organic acid the cannon might have brushed against on its own rolling over an anthill or stinging nettles or a pineapple rather than allow the white substance to proliferate with potentially damaging long-term side-effects.

Because the team’s work on the cannon occurred during regular museum hours, enabling numerous school groups to observe the process, Lanham says their preservation efforts also had an invaluable educational impact, inspiring the next generation of historians and conservators.

Dorset museum crowdfunds rare Bronze Age gold bracelet

Ancient, Treasures

The Dorset Museum & Art Gallery has raised the money to acquire a rare Late Bronze Age (950–750 B.C.) gold bracelet with a crowdfunding campaign to get them over the finish line.

The bracelet was discovered by a metal detectorist in Hilton, Dorset, in 2020. It is incomplete, a long fragment of a flat strip with a flared terminal. The strip was deliberately bent, folded over with the terminal on the inside. The other end was deliberately cut, not broken. The edges were raised to create low flanges on both sides. Comparison of the features of the band, particularly the flared terminal and low flanges, to similar pieces found in other locations confirmed that it was a bracelet dating to 950–750 B.C. The total weight of the gold is 14.05 grams (half an ounce).

The piece underwent the Treasure adjudication process, but the result was a foregone conclusion as it is more than 300 years old and composed of a precious metal. After it was declared treasure, a valuation committee of experts at the British Museum assessed its fair market value at £1,200 ($1,530).

As always, the museums closest to the find site are given the first chance to acquire the piece for the assessed value. Even a comparatively modest valuation is challenging for local museums with no acquisition budget to speak of, but the Dorset Museum & Art Gallery was highly motivated by the rarity and significance of the piece to Dorset’s history.

This item is a rarity in the county. Whilst Bronze Age gold objects are by their nature rare, those known from Dorset and dating to the Late Bronze Age only comprise a limited number of forms, and gold items are vastly outweighed by finds of base metal objects.

This item provides an indication that the deliberate modification of gold objects prior to their deposition continued into the Late Bronze Age in Dorset. Many Bronze Age metal objects were deliberately modified in antiquity, but this is not apparently related to treating the object as scrap, but rather carries some other social meaning within which larger objects such as bracelets and torcs were portioned and changed before entering the ground. This object is also significant for the location where it was found. The majority of finds of Bronze Age gold (and indeed bronze) objects have been recovered from the more north-easterly part of the county around Cranborne Chase. This was located in the centre of the county in the chalk valleys, an area which is rich in prehistoric archaeology but less researched and poorly understood.

The museum was keen to exhibit the piece, study it and share it with other researchers. They did not want to risk the piece being sold to a private collector. They were able to raise £720 on their own, which left just £480 ($612) to raise. The crowd pitched in with alacrity, and a week later the fundraiser was over with its goal easily met.

Pebbled mosaic floor of satyrs found in Greece

Ancient

A pebbled mosaic floor with a central scene of two satyrs has been unearthed in Eretria, southeastern Greece. The floor is part of a house from the Late Classical period and dates to around the middle of the 4th century B.C.

Eretria was founded in the Greek Dark Ages, so early that it even ranks a mention in Homer’s Illiad as one of the cities who sent ships to fight against Troy. Thanks to its success in trade, it was a regional power by the 8th century B.C., controlling Aegean islands, territories in central Greece and founding colonies on the northern Aegean coast, mainland Italy and Sicily. The prosperity of the city was reflected in the luxury of the private homes that began the appear in Eretria in the 4th century B.C. They were designed in the classical style with a central peristyle courtyard surrounded by the private rooms of the family and public areas where guests were welcomed on official occasions and celebrations.

The remains of the recently-discovered house were found during installation of a new water pipeline in the center of the ancient city where other important ancient remains have been found, including the sanctuary of Apollo Daphniforos, the Quarter of the Panathenaic Amphorae and the House of the Mosaics. The latter also dates to the 4th century B.C (ca. 360-350 B.C.) and as its name suggests, contains mosaic floors made in a similar pebbled style.

The excavation uncovered a room just under 12 feet square with surviving walls on the south and east sides. The floor was covered with small, white natural pebbles. In the center of the room is a circular medallion with small black pebbles as the background. Against the black backdrop are two nude satyrs with goat tails, pointed ears and horns. One is a beardless youth playing the double flute; the other is older, bearded and in motion, likely dancing to the music. The details of their faces and bodies are highlighted with pebbles in red and yellow as well as white and black, while both of the satyrs’ hair were rendered with the yellow pebbles.

A raised floor about an inch high was unearthed along the north and east sides of the room. This feature, found in other houses from the period in Eretria, was a platform where reclining couches were placed, identifying the room as a banqueting space. This dovetails with the motif of performing satyrs in the middle of the floor, as these rooms were used for celebrations, gatherings and entertainments.

The floor and structure of the house were disturbed in the early Christian era (5th-6th c. A.D.) when the abandoned dwelling was used as a cemetery. Five tombs were found there, one your basic pit tomb, the other with ceramic tile roofs. They had been dug into the embankment of the house and disturbed the mosaic floor. Another five tombs (again four with ceramic roofs, one pit) were found just outside the room on the other side of the south wall.

The floor has been temporarily covered for its protection while the water pipeline is redesigned so it does not interfere with the discovery.

Pot of Persian gold coins found in Turkey

Ancient, Treasures

Archaeologists have discovered a pot of Persian gold coins likely dating to the 5th century B.C. in the ancient city-state of Notion in western Turkey. The coins are gold darics, characterized by the image of a kneeling archer wearing a long tunic on the obverse. The reverse has no image, only a punch mark. They were likely minted in Sardis, 60 miles northeast of Notion, and were buried in a small wine jug known as an olpe.

Built on two promontories overlooking a bay on the Hales River where it meets the Aegean, Notion was a harbor town twinned with the inland city of Kolophon. The first textual record of the city dates to the 6th century B.C., but most of the archaeological remains in its current location date the Hellenistic period (3rd-1st century B.C.). Researchers believed it may have been refounded at that time, reconstructed with a planned grid structure, fortified walls, terracing for expanded residential neighborhoods and a complex water supply system.

Notion was largely abandoned after the 1st century A.D. The isolated location kept it from being rebuilt after its abandonment, and it is basically devoid of post-Roman construction. There has also been very little ground shifting or build-up to speak of, which makes its ancient remains extraordinarily legible on the surface. The University of Michigan’s Notion Archaeological Project has been documenting and excavating the site since 2014.

The 2023 excavation found remains pre-dating the Hellenistic reconstruction of the city, including pottery from the 5th century B.C. and a section of ancient wall that had been incorporated into the foundations of a 3rd century B.C. Hellenistic house. The pot of coins was discovered under the courtyard of the house. They had been buried in a corner of the older building that had once stood on that site.

A daric was the equivalent to one month’s pay for a soldier at that time, and were primarily used to pay mercenaries employed by the Persian Empire. This hoard may have been buried by a soldier involved in the conflicts between the Persian Empire and the Greek cities.

Notion was incorporated into the Persian Empire together with the other Greek cities on the west coast of Turkey in the mid-sixth century B.C. It was freed from Persian rule in the early fifth century B.C., but then reintegrated into the Persian empire in the early fourth century B.C. It remained a Persian possession until the conquest of Alexander the Great in 334 B.C.

Ancient historians frequently mention military operations around Notion. During much of the fifth century B.C., Notion, while freed from the Persians, lay under Athenian domination. The conflicting loyalties of the inhabitants of Notion and nearby cities, which occupied a border region between the Persian and Athenian spheres of influence, are illustrated by a dramatic episode related by the Greek historian Thucydides.

Between 430 B.C. and 427 B.C., a group of Persian sympathizers from the nearby city of Colophon had occupied part of Notion with the help of Greek and “barbarian” mercenaries. In 427 B.C., an Athenian general called Paches attacked and killed the pro-Persian mercenaries, after luring their commander into a trap. The Persian sympathizers were then expelled, and Notion was reorganized under Athenian supervision.

The archaeological context suggests these battles could be the background of the deposition of the hoard and its having been left behind instead of retrieved by the person who buried it for safety. However, the current chronology of Persian coins categorizes the darics found in the jug as 4th century B.C. The chronology may have to be rewritten because most the coin discoveries on which the scholarship is based were not made in their original archaeological context. In fact, this is the only Persian gold coin hoard in its archaeological context ever discovered in Asia Minor. One of the exciting aspects of the find is that it gives researchers the opportunity to correct the timeline of Achaemenid gold coinage based on the analysis of the archaeological stratigraphy and absolute dating of pottery found in the layer with the coins.

The gold coins are now at the Ephesus Archaeological Museum in Selcuk, Turkey, as are the Athenian pottery fragments recovered in the courtyard excavation.

Iron Age cremations buried around Bronze Age mound

Ancient

A Bronze Age burial mound surrounded by Iron Age cremation burials has been discovered in Petershagen, northwestern Germany.

Archaeologists excavated the site before expansion of a gravel mine after aerial photography revealed rich plant growth in a large circle. The vegetation, which contrasted sharply with the dry gravel around it, was a signal to the archaeologists that there was almost certainly a burial mound there. The mounds were bordered by ditches that were infilled with rich soil which provided a welcoming home for plant life, unlike the gravel.

The Westphalia-Lippe Regional Association (LWL) Archaeology unit followed up with test excavations based on the aerial data. They found a cremation burial almost immediately, and then more, both cinerary urns and graves consisting of funeral pyres buried after the ceremony. They were buried around the perimeter ditch of the burial mound, using the much earlier Bronze Age mound, which at that time would have loomed large on the landscape, as a monumental centerpoint of a necropolis.

The preliminary dating of the graves is based on the shapes and ornamentation of the urns. The earliest of them date to the 7th to 5th centuries B.C. when the Iron Age Nienburg group occupied the area.

According to the previous classification of the recovered finds, the cremation graves were buried in the ground between the 2nd century BC and the turn of the era. To date the graves without grave goods, the age will be determined using radiocarbon dating of charcoal. According to the scientists, surprises are always possible. The actual period of use of the necropolis can therefore only be clearly assessed in conjunction with the results of the scientific dating.

Sebastian Düvel, scientific advisor at the LWL Archaeology for Westphalia, on the new discoveries: “The monuments, which are still clearly visible centuries after they were built, represented an important reference point in the landscape. In this case, they were the central element for further burials in the 7th to 5th centuries BC and in the 2nd to 1st centuries BC. The new sites clearly consolidate the image of an extensive burial landscape with dozens of mounds and adjacent burials along the Westphalian Middle Weser.”