Stonehenge and glass-making : how things really happened

[Maciamo]

Re-reading Bill Bryson's Notes from a Small Island, I felt like commenting on two passages.

I will start with the first paragraph of chapter 9.

Among the many thousands of things that I have never been able to understand, one of in particular stands out. That is the question of who was the first person who stood by a pile of sand and said, "You know, I bet if we took some of this and mixed it with a little potash and heated it, we could make a material that would be solid and yet transparent. We could call it glass." Call me obtuse, but you could stand me on a beach till the end of time and never would it occur to me to try to make it into windows.

When I read that, I thought it was just a funny way of introducing his subject, glass. When I mentioned it to someone, he replied that it was a good question, a question without answer like "Which came first, the egg and the chicken ?" When I realised that he was serious, that left me flabbergasted. My friend is educated and far from half-witted, and yet he couldn't imagine how people first came around to make glass. It's the kind of thing that I instantly visualise in my mind.

There wasn't a person who got a genius idea by looking at sand and just knew that he could melt it and make glass. As we so many discoveries in history it was an accident, or rather a side-effect of another development, in this case metal working. The first civilisations to develop glass were Egypt and Mesopotamia, both regions were sand was abundant. If they haven't realised that some sand "glassified" after being in contact with fire at high temperature such as in a pottery kiln, or when melting copper or tin ore.

I checked it online to confirm my intuition, and the earliest remains of glass indeed date from the Bronze Age. This glass wasn't nice and solid transparent panes like on modern windows. Everybody knows that even windows a few centuries had a lot of imperfections, let alone 5000 years ago ! The first accidental glass might just have been small beads or shapeless conglomerate. It would have been brownish or yellowish and translucent at best, and much less resistant than modern glass.

The second passage is a few pages before.

I know this goes without saying, but Stonehenge really was the most incredible accomplishment. It took five hundred men just to pull each sarsen, plus a hundred more to dash around positioning the rollers. Just think about it for a minute. Can you imagine trying to talk six hundred people into helping you to drag a fifty-ton stone eighteen miles across the countryside and muscle it into an upright position, and then saying, "Right, lads ! Another twenty like that, plus some lintels and maybe a couple of dozen nice bluestones from Wales, and we can party !" Whoever was the person behind Stonehenge was one dickens of a motivator, I'll tell you that.

Bill Bryson has an amazing gift for playing with words and make each sentence, if not always funny, at least very pleasant to read. But his tendency to exaggerate and joke a lot sometimes makes me wonder when he is being serious. If he did write this passage seriously (and I think he did), he doesn't sound very different from the American tourist who wonders why they built Windsor Castle so near from the airport. That is a quite confused perception of time and history. It's just mystifying ! (if you will allow me this allusion to Stonehenge)

Stonehenge wasn't the project of one man. It is the largest religious site of Neolithic Europe, a monument used by tens or hundreds of thousands of people, living at least in the southern part of ancient Britain. It wasn't the work of a generation, but dozens of them. The site itself had been used for rituals since 8000 BCE. So when the first stones were erected around 3100 BCE, replacing the older wooden monuments, the place had been sacred for 5,000 years. It's about the same time frame as the one separating us from the pyramid builders in Egypt. If anything, it is actually surprising that they didn't start using stones before. I guess that the population was not large enough, as agriculture was only introduced into Britain around 4400 BCE and took a while to spread around become well established.

It took about 900 years to erect the main stone structure of Stonehenge, and another 500 years to rearrange and replace some stones to give them their modern disposition, hardly a remarkable achievement. As the main religious site of a whole country, it doesn't feel like a lot of dedicated hard work for tens of thousands of men to place a stone upright once every generation. The thing is, it was even slower than that. They must have been working on it very occasionally, when they had nothing better to do. So my feeling about it is just the opposite of Bill Bryson's and all the stupefied visitors who also fail to read the timeline. It's the biggest site of its kind in Europe, but this only tells us that people were a bunch of lazy bastards at the time.

 

[Tabaccus Maximus]

Re-reading Bill Bryson's Notes from a Small Island, I felt like commenting on two passages.

I will start with the first paragraph of chapter 9.



When I read that, I thought it was just a funny way of introducing his subject, glass. When I mentioned it to someone, he replied that it was a good question, a question without answer like "Which came first, the egg and the chicken ?" When I realised that he was serious, that left me flabbergasted. My friend is educated and far from half-witted, and yet he couldn't imagine how people first came around to make glass. It's the kind of thing that I instantly visualise in my mind.

There wasn't a person who got a genius idea by looking at sand and just knew that he could melt it and make glass. As we so many discoveries in history it was an accident, or rather a side-effect of another development, in this case metal working. The first civilisations to develop glass were Egypt and Mesopotamia, both regions were sand was abundant. If they haven't realised that some sand "glassified" after being in contact with fire at high temperature such as in a pottery kiln, or when melting copper or tin ore.

I checked it online to confirm my intuition, and the earliest remains of glass indeed date from the Bronze Age. This glass wasn't nice and solid transparent panes like on modern windows. Everybody knows that even windows a few centuries had a lot of imperfections, let alone 5000 years ago ! The first accidental glass might just have been small beads or shapeless conglomerate. It would have been brownish or yellowish and translucent at best, and much less resistant than modern glass.

As you've said, Maciamo, some discoveries are made accidentally. Incidentally, how discoveries were made accidentally are sometimes found accidentally. The answer is fairly easy as to how glass came about, as I found out. My first blast furnace was constructed of a 'self-made' refractory cement. "Real" refractory from a refractory dealer is incredibly dense and incredibly expensive. For example, if you work bronze or iron, you'll need a furnace capable of maintaining the right temperature, therefore, high quality insulating materials will be required. When I built my first, I used 'x' parts of silica play sand, 'x' part of bentonite (100% Walmart kitty litter) and a very small fraction of Portland cement. My initial goal was only to cast aluminum and so of course I did not need high quality refractory. I had actually substituted, substitutes for substitutes for substitutes and felt very smart and frugal about it. Because the quality of my aluminum sucked, I let the finance blow a little hotter than I should have. Several days later I was rebuilding the furnace and found 'huge' chunks of glass slag in the bottom structure.
During the late Bronze Age, smiters were probably experimenting with Iron and so forth. Because of the chemical constitution required of furnace materials, I would guess that metal smiths made lots of slag. They probably understood very well that it came from the silica and at what temperature the silica became plastic, but probably really didn't have a use for it other than decorative work. From a practical perspective, ceramic pottery is cheap and practical and the industry was well developed in those days. Glass was probably attractive artistically, but not practical for usual wares. At some point the economics work out and wha la, glass.