Tag: London

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Jimi Hendrix in London on his 81st Birthday November 27th 2023

Jimi Hendrix in Montague Place

To my mind, THE genius of the electric guitar, and a great songwriter.

Born Johnny Allen Hendrix in Seattle on 27th November 1942. He was spotted by ex-Animals Chas Chandler (bassist) when performing in small cafés In New York as Jimmy James. Chandler suggested he came to England. On the flight, they decided to change his name to Jimi. He arrived on September 24, 1966.

“It’s a different kind of atmosphere here. People are more mild-mannered. I like all the little streets and the boutiques. It’s like a kind of fairyland”

https://www.independent.co.uk Jimi Hendrix’s London.

On his first day in London, he met Kathy Etchingham, and she found them a flat on the upper floors of 23 Brook Street, which is now part of Handel&Hendrix in London. Now, a small museum to the two musical giants who lived next door to each other (if they were time travellers). For the English middle class, it’s comforting to know that Jimi bought the furnishings of the flat from their favourite, the nearby John Lewis Department store. He got his look from Carnaby Street and Portobello Road Market.

London wasn’t an arbitrary choice for a young American Bluesman. The wave of British Bands that came to international prominence in 1964, was based on the almost forgotten (by the mainstream media) Black American Blues legends such as Woody Guthrie and Ledbelly. Bands like the Rolling Stones, the Beatles, and the Animals loved this music, and began their careers playing cover versions in Clubs in London. (For more on the British Blues Revival, look here🙂

Hendrix’s younger brother, Leon, spoke about the importance of London to Hendrix

“He loved England ‘cos it was like Seattle. It was like home. It was the same climate, y’know? And this is where all the music was. This is where all of his friends were – Eric Clapton, The Beatles, the Rolling Stones, Brian Jones, everybody…”

He concluded: “After people played, they all went and jammed together. Like, when Jimi played a concert that was only the warm-up… After the concert, he was out and about lookin’ for somebody to play with and somebody’s studio to jam at. They’d just be jammin’ all night ’til, like, seven or eight in the morning. It was awesome.”

Reported in Mouth Magazine 2018 and quoted in https://faroutmagazine.co.uk

Chas Chandler was interested in managing bands, and thought Hey Joe, which he heard Hendrix play, could be a hit single. Hey Joe got to no 6, in Jan 1967) in the UK Top Ten, but failed to make an impression in the US.

Here is a YouTube film of Hendrix playing ‘Hey Joe’.

The Independent website above gives a good guide to Hendrix in London. An excellent documentary on Hendrix was recently aired on BBC Sounds, Everything but the Guitar. To finish off, just look at the bill on at the Saville Theatre.

One month in 60s London!

For details of Hendix Gigs look at the Set list Web site, which shows he performed at the Saville Theatre in Jan,May and June 1967 on his First European Tour, and again in Aug and Oct on his 2nd European Tour.

I have also revised my post on Stir Up Sunday!, which you might like to see.

First published on Nov 27th 2022, as part of Stir Up Sunday! And revised onto its own page on the same day, 2023.

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Elsyng Palace, Enfield Society Excavations

Elsynge Palace

I was interested in this site because it was one of the many palaces owned by Henry VIII, and it began as a moated manor house before a transition into a small red brick courtyarded Palace, as seen above. Henry had, if my memory serves me well, approximately 57 Palaces and Manor Houses. 16 in the London area and 11 along the River Thames

But what I really liked when I visited the website was the charm of this lovely video by the Enfield Archaeology Society. Now those who know the wonderful TV Sitcom called the ‘Detectorists’ starring Toby Jones, Mackenzie Crook, Diana Rigg and others, will recognise the styling of the amateur archaeologists – all looking like rumpled would be Indiana Jones’s! Very English.

https://www.enfarchsoc.org/elsyng/

The good news is that the show is having an extended Christmas Special outing this year.

I have revised and republished the following Almanac of the Past posts.

Night Fowling November 19th
Feast of St Edmund of East Anglia November 20th
Beginning of the Month of Frimaire November 21st
Martinmas Old Style – Pack-Rag Day November 22nd
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St Cecilia’s Day, Henry Wood and the BBC Proms, 17th November

St Sepulchre-without-Newgate, Musician’s Chapel, St Cecilia window. 17 August 2022, Andy Scott

Today, I’m publishing the stories of two Saints with London connections.

The first is for November 23rd, and I have extensively rewritten it. It is all about St Clements of Oranges and Lemons fame.

St Clements Day, the Blacksmith’s Holiday, the Early Church, Lydia and Wickham Day November 23rd

The second is from November 17th and is about St Cecilia and the London Proms, which you will find below:

St. Cecilia

St Cecilia is the patron saint of musicians.  She was martyred in Rome in the Second or Third Century AD. The story goes that she was married to a non-believer, and during her marriage ceremony she sang to God in her heart (hence her affiliation with musicians). She then told her husband, that she was a professed Virgin, and that if he violated her, he would be punished. She said she was being protected by an Angel of the Lord who was watching over her. Valerian, her husband, asked to see the Angel. So Cecilia told him to go to the Third Milestone along the Appian Way, where he would be baptised by Pope Urban 1 and would then see the Angel. He followed her advice, was converted and he and his wife were, later on, martyred.

The Church in Rome, Santa Cecilia in Trastevere, is said to be built on the site of her house, and has 5th Century origins. My friend, Derek Gadd, recently visited and let me use these photographs:

Santa Cecilia in Trastevere Photo by Derek Gadd
Santa Cecilia in Trastevere Photo by Derek Gadd

St Cecilia in London

There is a window dedicated to her in the Holy Sepulchre Church-without-Newgate, In London, opposite the site of the infamous Newgate Prison.  Henry Wood, one of our most famous conductors and the founder of the Promenade Concerts, played organ here when he was 14. In 1944, his ashes were placed beneath the window dedicated to St Cecilia and, later, the Church became the National Musician’s Church.

The memorial to Henry Wood at St Sepulchre is engraved:

This window is dedicated to the memory of
Sir Henry Wood, C.H.,
Founder and for fifty years Conductor of
THE PROMENADE CONCERTS
1895-1944.
He opened the door to a new world
Of sense and feeling to millions of
his fellows. He gave life to Music
and he brought Music to the People.
His ashes rest beneath.

The Concerts are now called the BBC Proms and continue an 18th and 19th Century tradition of, originally, outdoor concerts, and then indoor promenade concerts. At the end of the 19th Century, the inexpensive Promenade Concerts were put on to help broaden the interest in classical music. Henry Wood was the sole conductor.

Wikipedia reports :

Czech conductor Jiří Bělohlávek described the Proms as “the world’s largest and most democratic musical festival”.

The Eight-week Festival is held at the Royal Albert Hall. It moved here during World War 2 after the original venue, the Queen’s Hall, was destroyed in the Blitz in May 1941.

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Martinmas – Festival of Winter’s Beginning November 11th

Statue of St Martin at Ligugé

So, this is All Saints Day, Old style, also known as St Martin’s Day, one of the most important Christian festivals of the medieval world.

Father Francis Weiser in the Handbook of Christian Feasts and Customs suggests this was the Thanksgiving of Medieval Europe:

It was a holiday in Germany, France, Holland, England and in Central Europe. People first went to Mass and observed the rest of the day with games, dances, parades, and a festive dinner, the main feature of the meal being the traditional roast goose (Martin’s goose). With the goose dinner, they drank “Saint Martin’s wine,” which was the first lot of wine made from the grapes of the recent harvest. Martinmas was the festival commemorating filled barns and stocked larders.

It was celebrated with Bonfires in Germany, and with St Martins Beef and Mumming plays in England, but, following the Reformation, its place in the Calendar has been taken by Bonfire Day and Halloween.

St. Martin of Tours (died AD397) was a soldier in the Roman Army who would not fight because of his Christian beliefs. When he met a beggar, he cut his cloak in half and shared his cloak. He rose in the hierarchy of the Gallic Church and became Bishop of Tours. He is one of the few early saints not to be martyred and is the saint of soldiers, beggars and the oppressed. Furthermore, he stands for holding beliefs steadfastly s and helping those in need. According to legend, his barge on the River Loire was accompanied by flowers and birds.

Early 20th Century Image of Trafalgar Sq. St Martin’s is in the top right-hand corner.

There are two famous Churches dedicated to St Martin in Central London with possible early origins. St Martin’s in the Fields, near Trafalgar Square, has been the site of excavations where finds show a very early settlement there, with early sarcophagi. It is the one place where a convincing case can be made for continuity between the Roman and the Anglo-Saxon period. It is possible, that the Church was founded soon after St Martin’s death (397AD). A settlement grew up near it, and this expanded to become Lundenwic, the successor settlement to Londinium.

Old Print of London c1540 showing St Pauls, with St Martin's by the wall to the left of the photo
Old Print of London c1540 showing St Pauls, with St Martin’s by the wall to the left of the photo

The other St Martins is St Martins Within, just inside the Roman Gate at Ludgate. Many early churches are found at or indeed above Gates and this one also has legendary links to burial places for King Lud, and for King Cadwallo, or Cadwallon ap Cadfan, one of the last British Kings to have any chance of recovering Britain from the Anglo-Saxons. Geoffrey of Monmouth says that Cadwallo was buried here in a statue of a Bronze Horseman, and thereby to protect London as a ‘Palladium’ (see for more about Palladiums of London. It has been suggested by John Clark, Emeritus Curator at the Museum of London, that Geoffrey of Monmouth might have used the discovery of a Roman Equestrian Statue as an inspiration for the story.

St Martin was also the saint of Travellers, and this might explain the location of the Church near the gate. Although there is nothing but legendary ‘evidence’, it would make sense for an early church to be built near Ludgate, which is the Gate that leads to St Pauls which was founded in 604AD. Although the City might have been mostly empty, the presence of St Pauls means that Ludgate was most likely still in use or at least restored around this period. It also leads, via Fleet Street and Whitehall, almost directly to the other St Martin.

St Martin’s Day was also the time of year when lime plaster was renewed because lime needs to be kept moist when renewed. It takes three to four days to form the calcite crystals that make it waterproof.

(Originally, posted 11 Nov 2021, revised, Nov 2022, and 10 Nov 2023)

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William Shakespeare’s First Folio 400 Years Old Today 8th November

Droeshout Portrait of Shakespeare from the First Folio
Droeshout Portrait of Shakespeare from the First Folio

Four Hundred Years ago, on this day, 8th November in 1623, the First Folio was registered at Stationer’s Hall near the publishing district around St Pauls Cathedral in London. It was actually called

Mr. William Shakespeare’s Comedies, Histories, & Tragedies

Sketch of the First Folio by William Shakespeare

It was put together by his actor friends, John Heminge and Henry Condell seven years after his death, and they wanted to replace all the corrupt editions of his plays and poems that had been

“stol’n and surreptitious copies, maimed and deformed by frauds and stealths of injurious impostors”.

The true texts of his plays and poems “are now offer’d to your view cured, and perfect of their limbes; and all the rest, absolute in their numbers as he conceived them.” Wikipedia

In fact, the plays were ready early as they entered in to the catalogues for the Frankfurt Book festival to appear between April and October 1622,- and how amazing is it that, that festival is still the dream of any aspirant writer?

The First Folio offers plenty of proof that Shakespeare was the author of the plays. He left gold rings of remembrance to Heminge and Condell in his Will. They were part of his Players Company, and had worked together on many of the plays. The Folio has forewords by people extolling the virtues of the writer. Enough proof for any reasonable person.

Heminge and Condell are commemorated in the Garden of St Mary Aldermary behind the Guildhall, where they were Churchwardens, and not far from where Shakespeare was living in 1611. True friends.

St Mary Aldermany monument to Shakespeare, Heminge and Condell and the First Folio.
St Mary Aldermany monument to Shakespeare, Heminge and Condell and the First Folio.

There is a wonderful BBC festival of Shakespeare on at the moment. Have a look at it here:

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27th June 1967 World’s First ATM Honoured. Digital Heritage –

Screenshot from Londonist Web Page

On the 10th April 2023, Heritage England announced on its webpage, that they had listed a Bank which contained the world’s first ATM Machine. Barclays Bank choose its Enfield Branch for this honour which opened on 27th June 1967. Above, you will see local celebrity, Reg Varney (in hat), a star of a very popular and ‘corny’ sitcom called ‘On the Buses.’ opening the new machine. It miraculously delivered a £10 note without any human intervention, and offered access to money after banking hours.

1967 Ten pound note

Barclay’s had previously launched the UK’s first credit card, and selected Enfield to be the place where they launched an automatic machine to dispense money – nicknamed ‘money machines’ in the UK. The customer was issued a ‘punched card’ and had to enter a PIN for the magic to be initiated. Barclays were developing the idea of a magnetic strip on a card at the same time.

Google Street View image of the Enfield Barclays Bank (screenprinted 15/07/23)
Google Street View image of the Enfield Barclays Bank (screenprinted 15/07/23)

The building, which has a plaque and a gold-painted modern ATM, is Grade II listed and so should be protected from development in future. The building itself is an interesting, almost typical, late Victorian red brick commercial building, with fine details in the Flemish Renaissance style by William Gilbee Scott. Scott lived in Enfield.

I look forward to visiting it on my next visit to Enfield Lock on my narrow boat Mrs Towser.

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June 24th Festival of St John the Baptist

St John the Baptist Church Walbrook. London from the online
St John the Baptist Church, Walbrook. London. From the online Agas Map

On my post of June 3rd I wrote about the street festivals in the Tudor City of London to celebrate the feast day of saints. I promised to continue the story on the Feast day of St John (24th June). This is set out in full below. It includes the Feast Day of St Peter and Paul (29th June) What is amazing is the scale and the expense of the celebrations.

These Saints are some of the most important in the Christian Calendar. John being the forerunner to Jesus and his cousin, and Peter and Paul being the apostles who, more than anyone else, created the Christian Church.

There are also pagan rituals associated with the Feast of St John. Here is an example of French pagan solstice fires:

“They were lit at the crossroads in the fields to prevent witches and sorceresses from passing through during the night; herbs gathered on Saint John’s Day were sometimes burned to ward off lightning, thunder and storms, and it was thought that these fumigations would ward off demons and tumults.”

For more information, have a look at ‘French Moments’ here:

The Feast of St John is often described as being on the Summer Solstice, it isn’t by modern reckoning, but nor is December 25th the Winter Solstice. But they were celebrated as such by Christians, and the Solstice can be thought of as spread over 3 or 4 days (or more if taking into account Solstice Old style. The major events of the sun and the moon were linked into Christian theology and symbolism. Jesus, son of God, would clearly have arrived on the auspicious time of the Winter Solstice. His cousin, John the Baptist, came to tell the world about the coming of Jesus and so his birthday was exactly 6 months before at the Summer Solstice.

St John is also special as most Saint’s Days are linked to the day of their death, but June 24th is the birthday of St John. His beheading by Herod is commemorated on 29th August.

St John the Baptist upon Walbrook in the City of London is first mentioned in the 12th Century, burnt down and not rebuilt after the Great Fire of London. The parish was united with St Antholin, Budge Row, The Graveyard survived until 1884 when the District Line destroyed most of the Graveyard and the bones were reinterred below a monument, which can still be seen in Cloak Lane.

Here is what John Stow tells us about the processions on the night before the feast of St John (24th June) and St Peter and Paul (29th June):

On the vigil of St. John the Baptist, and on St. Peter and Paul the Apostles, every man’s door being shadowed with green birch, long fennel, St. John’s wort, orpin, white lilies, and such like, garnished upon with garlands of beautiful flowers, had also lamps of glass, with oil burning in them all the night; some hung out branches of iron curiously wrought, containing hundreds of lamps alight at once, which made a goodly show, namely in New Fish street, Thames street, etc.

Then had ye besides the standing watches all in bright harness, in every ward and street of this city and suburbs, a marching watch, that passed through the principal streets thereof, to wit, from the little conduit by Paule’s gate to West Cheape, by the stocks through Cornhill, by Leaden hall to Aldgate, then back down Fenchurch street, by Grasse church, about Grasse church conduit, and up Grasse church street into Cornhill, and through it into West Cheape again.

Grasse Church Street is Gracechurch Street.

The whole way for this marching watch extendeth to three thousand two hundred tailor’s yards of assize; for the furniture whereof with lights, there were appointed seven hundred cressets, five hundred of them being found by the companies, the other two hundred by the chamber of London.

Note a cresset is: a ‘metal container of oil, grease, wood, or coal set alight for illumination and typically mounted on a pole’ (Wikipedia).

Besides the which lights every constable in London, in number more than two hundred and forty, had his cresset: the charge of every cresset was in light two shillings and four pence, and every cresset had two men, one to bear or hold it, another to bear a bag with light, and to serve it, so that the poor men pertaining to the cressets, taking wages, besides that every one had a straw hat, with a badge painted, and his breakfast in the mornings amounted in number to almost two thousand.

The marching watch contained in number about two thousand men, part of them being old soldiers of skill, to be captains, lieutenants, serjeants, corporals, etc., wiflers, drummers, and fifes, standard and ensign bearers, sword players, trumpeters on horseback, demilances on great horses, gunners with hand guns, or half hakes, archers in coats of white fustian, signed on the breast and back with the arms of the city, their bows bent in their hands, with sheaves of arrows by their sides, pike-men in bright corslets, burganets, etc., halberds, the like bill-men in almaine rivets, and apernes of mail in great number;

there were also divers pageants, morris dancers, constables, the one-half, which was one hundred and twenty, on St. John’s eve, the other half on St. Peter’s eve, in bright harness, some overgilt, and every one a jornet of scarlet thereupon, and a chain of gold, his henchman following him, his minstrels before him, and his cresset light passing by him, the waits of the city, the mayor’s officers for his guard before him, all in a livery of worsted, or say jackets party-coloured, the mayor himself well mounted on horseback, the swordbearer before him in fair armour well mounted also, the mayor’s footmen, and the like torch bearers about him, henchmen twain upon great stirring horses, following him.

The sheriffs’ watches came one after the other in like order, but not so large in number as the mayor’s; for where the mayor had besides his giant three pageants, each of the sheriffs had besides their giants but two pageants, each their morris dance, and one henchman, their officers in jackets of worsted or say, party-coloured, differing from the mayor’s, and each from other, but having harnessed men a great many, etc

John Stow, author of the ‘Survey of London‘ first published in 1598. Available at the wonderful Project Gutenberg: ‘https://www.gutenberg.org/files/42959/42959-h/42959-h.htm’

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Digital Heritage – the Picture Room at the Sir John Soane Museum

Screen Shot of the Virtual Tour of the Sir John Soane Museum showing the approach to the Paintings Room
Screen Shot of the Virtual Tour of the Sir John Soane Museum

The Sir John Soane Museum is my second favourite London Museum. It’s the place I choose to take people who don’t know London. What I like about it is the atmosphere. It’s not a place I go because of the collection, it’s a place I go because I’m just awestruck when I enter the doors.

Architect Soane, made a Museum of his house, filling it with architectural and sculptural pieces but also some stupendous Art, particularly paintings by William Hogarth. But that isn’t my motivation to keep going back. It’s the Picture Room (and the domed ceilings). Soane had a great collection of paintings, but not enough walls. What he did was to design the Paintings Room. When you visit you go in, admire the paintings on the wall, and the attendant comes in, opens a shutter, and behind the great paintings are another wall of great paintings. And then he opens another set of shutters, and there, is another feast for your eyes.

Now, they have made high quality digital images of the rooms, and put them together using photogrammetry into a digital model which you can explore.

So, feast your eyes on it here: (choose Picture Room from the three options).

It’s not quite as user-friendly as it might be. Firstly, when the tour delivers you to the Picture Room, you have to take over control to go in and explore the 360 degree image of the room. Unfortunately, the pictures are not clickable, so you cannot get information about them from here. Also, the ‘hot spots’ which allow you to open the shutters, only reveal themselves, on my computer, if you approach them at a certain angle.

But don’t let this put you off, I’m sure you will find your way around. So go into the Room, look around, move the cursus, and you will see little signs pop up which open and close the shutters. Really, do try it! There are a couple of other rooms to explore too.

Here is a link to descriptions of the Picture Room and the paintings.

Oh, and the Dome Ceilings? Soane was a specialist in buildings that didn’t want windows in normal places. He was the architect of the Bank of England where windows in the walls were a security risk, and also of London’s first purpose built art gallery – the Dulwich Picture Gallery. Windows reduced the space for paintings, so he designed special low domed ceilings, and the Soane Museum is full of his experimentation in the form.

Scara Brae Three D Model

Another delight is the 3D model of Scara Brae which allows you to explore the Neolithic village, and walk around it. There are labels on this one, so you do get information too.

https://www.historicenvironment.scot/about-us/news/new-digital-model-of-skara-brae-welcomes-virtual-visitors/

360 Degree Panorama Virtual Tours. My part in their development.

I was an early adopter of this form of virtual reality, setting up virtual tours of the Old Operating Theatre Museum in the 1990’s. I have a draft post of this which I have been awaiting time to finish, which I hope to finish soon….

Thanks to the Museum’s Journal article on Photogrametry of May/June 2022 for the two examples above.

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Walks 2023 – February – June

I am working on a new season, and these are the walks for the first six months – but more to come.

The Archaeology Of London Walk Sunday 2nd April 2023 11:15 Exit 3 Bank Underground Station To book
Jane Austen’s London Sat 2.30 pm 2nd April 2023 Green Park underground station, London (north exit, on the corner). To book
Chaucer’s Medieval London Guided Walk Aldgate Tube Sunday 16 April 2023 11.30pm To book
Chaucer’s London To Canterbury Virtual Pilgrimage Sunday 16th April 2023 7.30pm To book
The Peasants Revolt Anniversary Guided Walk Aldgate Underground Sunday 11th June 2023 10.45am. To book
The Peasants Revolt Anniversary Virtual Tour Sunday 11th June 2023 7.30pm To book

For a complete list of my walks in 2023 look here

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Mystery of Roman Concrete Solved?

Image credits: Concrete Interior or the Pantheon, FLICKR / CC BY-SA 2.0

The Society of Antiquaries Salon Newsletter has a fascinating report on an analysis of the virtues of Roman Concrete. Working as an archaeologist in the City of London, Roman concrete (opus signinum and opus caementicium) has long been a fascinating subject upon which I have pontificated (without a huge amount of research).

I first came across it at the GPO site just north of St Paul’s Cathedral and what I remember is the contrast to the sandy mortar of 10th/11th Century St Nicholas Church which we were also excavating.

Roman cement, which was pink, was incredibly hard. Medieval mortar was yellow and soft. You could successfully get through the medieval stuff with a trowel or, if you had to, with your finger nail. But opus signinum required a kango pneumatic drill. Properly, signinum has fragments of pottery bonded into the concrete, but we also found it used without inclusions.

Roman Cemement – Opus Signinum

According to the 10 Books of Architecture by Vitruvius (Marcus Vitruvius Pollio) it should be made using volcanic ash which outcropped around Rome and Naples. Without volcanic ash in Britain, the Romans ground down tiles/bricks and added it to lime and sand to make a very effective cement. It was often then ‘reinforced’ by using a mixture of cement and rubble limestone in the core of a wall.

As medieval Londoners dug under the City during building work or while digging pits, they often struck unlucky by hitting some rock-hard Roman foundations. The legend spread that the Roman cement was so hard because it was made of a magical formula that contained Bull’s Blood. (It was also normally said to be built by Julius Caesar!)

The Roman cement was also made in a water-proof version, allowing Roman amphitheatres to be flooded for naval re-enactments. All proper Roman archaeologists have also paid homage by going to Rome to see the totally amazing domed roof of the Pantheon, commissioned by Augustus’ right hand man Marcus Agrippa. Marcus Agrippa (27 BC – 14 AD).

So, this article by the Salon gives some explanation as to how the concrete vault of the Pantheon roof can have stayed up for 2,000 years and defied inevitable cracking. I have copied it word for word, (I did once ask if they minded and they said no) but also give a link to the original below.

By the way, the GPO site was a landmark in Roman Archaeology because it completely changed the view of early Roman London when we discovered densely occupied Roman houses, a long way outside of the area thought to be the core of the early City. And Vitruvius’s book on architecture is well worth reading. I might add a sample tomorrow?. Finally, I remember reading that when the Custom House in London suffered a collapse after only a few years, it was rebuilt by Robert Smirke (who also bulit the Classical British Museum building) using a new formulae for cement was is said to be the first concrete in Britain to surpass the quality of the Roman original.

https://mailchi.mp/sal/salon-issue-547287?e=34bc1ba8ed#edhighlights

‘Analysis of Roman Concrete Reveals Self-Healing Properties

Many of us will have stood in the Pantheon in Rome and wondered how this beautiful structure can still be standing today. It is the largest unreinforced concrete dome in the world, built under the emperor Hadrian in 126 AD. Researchers have recently been analysing the content and technique of mixing Roman concrete to identify why it has lasted so long and they may have uncovered its secret.

Admir Masic, Professor of civil and environmental engineering at Massachusetts Institute of Technology, led the research project, working with Harvard University. In his paper published in Science Advances, Masic explains that Roman concrete contains millimetre-scale white lumps known as lime clasts, which may have helped seal up cracks, formed over time.

The Romans made concrete by made by mixing lumps of volcanic rock and other aggregates, together with a mortar such as volcanic ash, a source of lime (calcium oxide) and water. The lime clasts found were ‘porous with cracks’ and had most likely been formed at a high temperature in a low water environment. This suggests the quicklime was not mixed with water before it was added to the other ingredients as is the case in modern concrete, but was mixed with the ash and aggregates first. This ‘hot mixing’ produces heat, which helps set the concrete and reduces the water content around the lime clasts.

This means that, if subsequently, water seeps into the Roman concrete, it will dissolve the calcium carbonate and form new calcite as it passes through the lime clasts, which will help to seal up any cracks that have formed. Indeed, cracks filled with recently formed calcium carbonate have been found in Roman concrete.

Masic and his team tested this theory out by creating chunks of Roman-style concrete, containing cracks 0.5mm wide. They ran water over the concrete and in the samples containing lime clasts, within two weeks, the cracks sealed over with newly-formed calcite. Control samples of the concrete made without the lime clasts, did not seal.

Masic believes modern construction techniques could learn something from the Romans; ‘Roman-inspired approaches, based for example on hot mixing, might be a cost-effective way to make our infrastructure last longer through the self-healing mechanisms we illustrate in this study.’ An added bonus is that the development of a more resilient concrete ‘could help reduce the environmental impact of cement production, which currently accounts for about 8% of global greenhouse gas emissions’.

Image credits: Concrete Interior or the Pantheon, FLICKR / CC BY-SA 2.0′