It's all about.... Metal

A few weeks ago the Roman Baths had their exciting Science and Engineering week! Every day for a week there was a mix of science experiments and/or a display table. One of the display tables was created by me and I chose to talk about Metals. Here is the inside low down behind the metals the Romans would have had at their disposal throughout the Roman Empire.

Planning my table with Zosia

Gold
One of the world’s most desired metals even today! Gold in the Roman Empire was mined in various locations including Spain, Portugal and Dolaucothi in Wales. This metal’s soft properties and malleability made it easy to beat it into different shapes. It was a favourite metal to make into jewellery such as necklaces, bracelets, brooches and rings.

Silver
Roman currency relied on high supply of silver bullion. Silver was mined in various locations of the empire including Gaul, Greece and Asia Minor. In the mid 2nd century it was estimated 10,000 tons of silver was in circulation. This shiny, soft metal was used for jewellery, coins and utensils. Silver was also used to treat infections or illnesses.

Lead
Lead was commonly used in the Roman world because it was easily extracted and easy to work with. This metal was mined in various areas including central Europe, Spain, Britain and Greece. Lead was used for Roman piping because of its highly malleable and ductile properties. Lead’s symbol is Pb, which is the abbreviated word Plumbum in Latin. Plumbum, as you guessed it, derived later into the English word ‘Plumbing’.

Iron
Iron is the 6th most common element found in the universe. At the height of the Roman Empire it is estimated that approx 82,500 tons of iron was circulated annually. Under Roman rule iron became a very popular metal and its use intensified. This metal was used to create weapons and tools for everyday Roman life.

Bronze

Bronze is an alloy consisting mainly of copper and 1/3 tin. Copper was mined in various areas including Gaul, Cyprus and Arabia. Romans would tear down local religious bronze sculptures within the empire and melt the metal to make armour, weapons, tools and coins. As the Roman Empire expanded, to help the Roman budget, less precious metals like bronze were used more often for coins instead of gold or silver.

Pewter
Pewter is an alloy consisting 80-90% tin and 10-20% lead. Tin was mined in areas such as Iberia, Persia and Roman Britain. Pewter is a good conductor of heat and is sometimes used for cooking and tableware. Surviving examples of pewter can be found from Roman Britain dated around 3rd and 4th century AD.

For a link to just some of the metals within the Roman Bath's Collections please follow this link:
http://www.romanbaths.co.uk/explore/Search_Details.aspx

Solange - Collections placement

It's all about.... Glass

I really loved putting together a handling table about glass for National Science and Engineering Week, because I discovered so much about the history of glass and the science behind glassmaking. The enjoyment levels had nothing to do with looking through lovely artefacts at all…really!



My handling table and me...

 The objects I chose were perfectly suited to a timeline, showing the development of glassmaking techniques and its uses from obsidian (the only naturally occurring glass, formed by lava floes), through to modern glass jewellery made using techniques and colorants first developed over 2,000 years ago.

It was the Romans who revolutionised glassmaking through the invention of glassblowing. This technique works because atoms and molecules move around freely in molten glass, and do not form a crystalline structure when it cools, as they do in most other materials. Cooling glass stays flexible and can be manipulated by blowing a bubble into it through a long tube, and pulling it into various shapes before it hardens.

The technique of glassblowing is still used today, and the composition of modern glass is also very similar to Roman examples, consisting of:

• Sand (silica), the ‘former’. 65-70% of the overall mixture

• Soda, the ‘flux’. 15% of the overall mixture, which allows it to fuse more efficiently

• Lime, the stabiliser. 10% of the overall mixture, which makes it more durable and chemically resistant

• Pieces from malformed, broken, or old vessels, the ‘cullet’, which lowers the temperature of fusion

• Various impurities or colorants make up the remaining 5-10%

These colorants were usually powdered metals, and once again those used to colour ancient glass are still well known. Some of the most common include:

• Iron (Fe), which gives a pale blue, bottle green, amber or black. This is often used to colour wine bottles, although Chromium (Cr) is more commonly used today

• Manganese (Mn), used to create purple or yellow, and sometimes as a decolourant – clear glass was highly prized

• Copper (Cu), usually used for blue, green, ruby red or opaque red, but most recognisable as a turquoise colour

• Cobalt (Co), also used for rich deep blue, particularly in glass containing potash (burnt wood and bracken)

There were also more unusual colorants, including Uranium (U), which was used by 19th Century glassmakers who were unaware of the dangers of radiation, and creates an almost fluorescent yellow!

Roman Glass from Museum Collection BATRM 2003.22.8

It’s incredible that these ancient techniques and recipes are still widely used in the modern world, but what I find most unbelievable is the concept of their invention – what does it take to decide to stick a pipe into a red hot molten lump of sand and blow, I wonder!?

Zosia - Collections Intern

It's all about...... Roman aqueducts

To many people the words “Roman aqueduct” conjure up an image of huge arched monuments striding across a landscape and is one often used in pictures to portray the Romans.

But to a Roman citizen an aqueductus meant literally “water that’s lead from one place to another” or “water duct” and so the word was used for the whole length of piping or channels that carried water from source (often a spring) to a city or an industrial site. They could run great distances; one supplying Carthage in Tunisia was 132km long!

The earliest known Roman aqueduct was the Aqua Appia in Rome, built in 312BC. The Aqua Claudia also took water to Rome, but only 15km of its 68km length was raised on arches. We know quite a bit about the ones that supplied Rome as one of the men in charge of them (the curator aquarum!), called Frontinus, wrote a book on the subject.

Vallon Des Arcs, Barbegal

In Barbegal, southern France an aqueduct fed water to 16 water wheels which operated flour mills.

Most of the aqueducts relied on gravity: the water flowed from higher ground to low ground and followed a carefully surveyed gradient around a hillside. The aqueduct supplying Nimes in southern France had a gradient change of only 34cm per kilometre.

Sometimes to keep the route of the water flow at the right height, Roman engineers tunnelled through hills, and even ran siphons in watertight pipes up hill.

Castellum aquae

Once the water had arrived at a town it was held in a castellum aquae (or water tower) at the highest point of the settlement, which acted like a header tank in a modern house. This would create enough pressure to send the water through the town in smaller pipes.

In Britain we have little evidence of Roman aqueducts. The best example is near Dorchester, in Dorset, where channels along hillsides have been found that fed water to the Roman town of Durnovaria And every town and fort must have been the same, Bath included. Although the Roman town of Aquae Sulis had its hot water springs it needed cold water for the cold plunge baths, latrines (toilets), domestic supplies and perhaps even street fountains, the only source of clean water for most people. Unfortunately with all the later developments in the city nobody’s found any evidence …yet!

Pont du Gard

The Roman aqueduct now called the Pont du Gard which supplied Nimes, is 48.77m high.