Reverse engineering

[Boreades]

Granted Kaolin is plentiful in Devon and Cornwall. Especially around St. Austell.

Not sure how you get Sodium Carbonate from an Aluminium Silicate.
Al2 Si2 O5(OH)4



http://www.cornwalls.co.uk/history/indu ... a_clay.htm

Wood ash is a v.useful ingredient. Geopolymer.org says "The ashes of plants are also rich in lime and the priests established the custom of receiving ashes from cooking fires from all over Egypt, to add them to the mixture."

No doubt the mines that were smelting metal ores would have had plenty of wood ash.

[macausland]

You get the sodium carbonate by burning the samphire and other sea plants.

Samphire and similar plants are known as glassworts or saltworts.

https://en.wikipedia.org/wiki/Samphire

[hvered]

Saltworts were shown on TV yesterday evening. They were described as pioneer plants being colonisers of sand dunes on the Cumbria shoreline... re reverse engineering, the presenter said about 100 feet of land had been reclaimed in the last thirty years thanks to specialised plants including marram grass.

They reminded me of samphires I saw near Rocquaine Bay, a sandy beach on the west coast of Guernsey, but seem relatively rare. The wiki article says glass making workshops were located in places where saltworts grew but presumably glass makers were mainly interested in the sand and any plant would do for potash.

[macausland]

Here's an interesting site that advocates the use of sodium carbonate in the making of cement and concrete.

http://www.livescience.com/38376-green- ... f-bts.html

They support the idea that the Egyptians used concrete blocks in the construction of the pyramids.

'If you want to cook up some environmentally friendly cement, just mix two cups of granulated garden limestone, one cup of ground granulated blast furnace slag and three tablespoons of soda ash (i.e, sodium carbonate). What results is a strong, sustainable and economical alternative to ordinary Portland cement (OPC), the industry leader in cement. Researchers in Michel Barsoum’s group at Drexel University have been cooking up this seemingly new technology over the last several years, but its origins go back much farther than one may realize.

To the Great Pyramids of Egypt, in fact. Barsoum’s group had conducted research that seemed to prove some of the stones in the pyramids were cast using an early form of cement, rather than carved out of limestone. If some of the materials used to build the pyramids were indeed cast, and have lasted for 4,500 years, why not use them in today’s building materials, he wondered?'

[Boreades]

An excellent find.

Here in deepest East Wiltshire we have plenty of garden limestone. Hills full of it in fact. Also plenty of wood ash from our own log fire.

Am I right in thinking all we need now is a readily-available pile of soda ash? Like this (but closer).

I feel a theme emerging for a TME Summer Camp. Bring your own bucket and spade to join in the fun and start making Megalithic Sandcastles. Drink the local beer that's made from spring water that drains from the Ridgeway. Book early to avoid disappointment.

[macausland]

Today's Independent has an article about ancient arches which apparently are not the work of erosion but of gravity and internal stresses.

Like Michelangelo's sculptures the figure is already inside waiting to come out.

The expert who discovered this based his findings on Czech quarry workers who blasted rock away leaving arches and other formations.

So, it's not just gravity, it's also people with explosives blasting the rock.

Which brings us to square one so to speak.

'You can control it completely," Dr Bruthans told the BBC. "You select the pillar direction, by choosing the points where you apply the compression. It's just the stress which controls the shape - nothing else."

Which seems to suggest that sea arches and other structures could very well be artificial after all.






The first image is a natural sea arch. The second the 'man made laboratory arch'.

http://www.independent.co.uk/news/scien ... 18627.html

[hvered]

Just last week we were looking at Beaucette Marina on the north-east point of Guernsey, convinced it was a Megalithic harbour



only to be told by a local resident that the marina owed its existence to the Royal Engineers blasting the rocks!

This is true but what he didn't tell us is this was a former quarry and the operation, estimated to take three weeks, wasn't entirely straightforward.

Soon, it was realised that the original estimate was somewhat over-optimistic for three reasons. The immense strength and stubbornness of the blue Diorite granite prevented the usual method of removing rock by boring holes from the top; the hope that the sea together with the effect of the tides would be sufficient to open the channel (it wasn’t); and finally, a severe storm tossed 600 tons of previously excavated rock back into the opening.
After three months of back breaking work, work was suspended on 8th October 1968 and the Royal Engineers returned to the mainland.

A further reconnaissance was ordered in November to assess the situation. With 80% of the rock already removed, the survey concluded that 2 officers with 60 other ranks could complete the task between 17 February and 6 June 1969.

In February 1969, the Royal Engineers’ landing craft arrived in L’Ancresse again, and the familiar offloading of explosives and plant began.

It took seven months in the end but it seems to have worth the effort. Blue diorite granite from this quarry was used for the steps of St Paul's in London though the main source of granite appears to have been the Chausey Islands, further south, nowadays all but quarried out.

[Marko]

The Chinese (again!) are said to have invented gunpowder at an unspecified time, twelfth century or earlier since the Mongols were supposed to have used gunpowder. Perhaps it was used in a mining context, to blast rocks a la Royal Engineers?

Usually military artefacts seem to be precursors to industrial/commercial uses rather than vice versa but the Chinese don't seem to have been seen as terrifying warriors in the way the Mongols were portrayed.

[Boreades]

Ancient mines in Cornwall is exercised as a topic here
http://www.aditnow.co.uk/community/view ... spx?t=9578
by mining enthusiasts, with the opinion that
"There are more proven Bronze age workings than Roman."

[Mick Harper]

What a weird forum. Which reminds me, we need slightly out-of-the-mainstream forums that deal with physical geography, climatology, hydrology, hydrography, deserts ... stuff like that. Let us know of any you've come across (and whether you are a member or not). Either stick it here, or e-mail me or Hatty.