Glass and Game of Thrones
June 10, 2012 9:49 AM   Subscribe

I'm watching Game of Thrones and noticed that often the windows do not have glass, and yet I think I sometimes see glass trinkets. Glass seems like a very important technology because it keeps out bugs but allows in light, which sounds pretty useful when disease travels by insects and the winter is coming. When does glass begin to become a common-place part of domiciles, and what benefits did it mainly have for human civilization when it began to be more widely used in architecture? Is technologically feasible for the world of Game of Thrones, and if not, what are the main constraints?
posted by scunning to Technology (52 answers total) 16 users marked this as a favorite
Interesting observation. Glass has been around for a thousand years at least, but it's important to re,e,her that Game of Thrones doesn't take place in our history, so it's hard to infer what is technologically feasible for them on the basis of our history of technological development.
posted by dfriedman at 9:54 AM on June 10, 2012 [1 favorite]

but it's important to re,e,her that Game of Thrones doesn't take place in our history

But it is loosely modeled after the War of Roses which does take place in our reality. Without having any specific dates, I would imagine it becomes common-place as the cost and ease of manufacturing goes down.

I would think it's uses are obvious. Keeps both warmth/cool air out/in from entering/escaping. It provides a level of security and privacy that are not afforded with gaping holes that exist within the structure of the home.

I'll let the history nerds take it over from here.
posted by Fizz at 10:04 AM on June 10, 2012

Glass exists and is technologically feasible in the Game of Thrones world.
posted by J. Wilson at 10:05 AM on June 10, 2012 [2 favorites]

I imagine it's just easier to light and shoot sets when the windows have no glass in them to stop reflections of the crew etc
posted by fearfulsymmetry at 10:08 AM on June 10, 2012 [4 favorites]

What technology does it require? They smelt ore to make metal swords, and by all appearances, they appear to have some pretty good blacksmiths in this world. Is smelting sufficient knowledge as a base for the craft of making glass though?

For instance, I saw in one of the brothels glass but it was small vial glasses. Making large panes of glass and making small pieces of glass -- I imagine that requires more than just knowledge about the process. Window panes are more fragile, and manufacturing them in large sizes is probably challenging to do well.

That said - this is a civilization that would tremendously benefit from glass windows because of their vulnerability to the elements.
posted by scunning at 10:09 AM on June 10, 2012

J. Wilson -- glass windows though? I see the glass, but I don't see glass windows. But perhaps I'm missing them?
posted by scunning at 10:10 AM on June 10, 2012

Glass has been around basically forever. The Mesopotamians were mucking about with it in 3500 BC. Glass windows don't seem to have shown up until the Romans introduced it in the first century AD, but they weren't commonplace until the seventeenth century AD.

This is one of those things where the physical implements existed before the techniques to use them were developed. For example, glass was around for over three-thousand years before the Phoenicians perfected glass blowing in the first century BC. Why? No one knows. Why didn't the Romans invent steam power? They had all the relevant technology, and the Greeks knew about steam rotors. But no one put the pieces together until AD 1698.

Also, glass is a relatively resource- and time-intensive product, so it would probably take a level of prosperity well in excess of anything that exists in Westeros during the period in which the books are set before anything like a true glassmaking industry could exist.
posted by valkyryn at 10:10 AM on June 10, 2012 [9 favorites]

The ancient Romans had glass for trinkets but not for windows, mostly, although some cast glass windows have been discovered in Roman archaeological sites dating back to about 100 CE.

There were plenty of glass vessels and ornaments in England during the War of the Roses, but no glass windows.

In England, glass windows didn't really catch on until the 17th century, but as others have said, George R.R. Martin's universe isn't exactly like Earth. I mean, there are dragons.
posted by Sidhedevil at 10:13 AM on June 10, 2012 [1 favorite]

Oh, and the first glass windows were of blown glass. There's a common myth that old windows are thicker at the bottom because glass "flows" over time. This is incorrect. Rather, windows were made out of very large blown glass bubbles, so large that a small pane would seem flat, but which were almost never of uniform thickness. The thicker end of the pane was put on the bottom to prevent water from collecting.

That aside, this means that to make a glass window, you need to be able to make a really, really big bubble. Which involves both significant skill and technique, but also a pretty awesome glass recipe. This seems to be the kind of thing that one could spend a long, long time perfecting.
posted by valkyryn at 10:13 AM on June 10, 2012 [15 favorites]

valkryn -- 17th century. Then it sounds like glass production is something that the Industrial Revolution influenced in terms of its availability and use. Why is that? Is glass panes for windows something that requires a lot of specialization and division of labor, such as with a modern firm? I don't see many firms in Game of Thrones. It's usually more like a single operation without much division of labor. Even the blacksmiths seem to be people who ultimately control every part of the overall process of production.
posted by scunning at 10:13 AM on June 10, 2012

Just because something is invented doesn't mean it's going to catch on. The Aztecs knew about the wheel--it just wasn't particularly useful to them. Telephone-line faxes were invented in 1902 or 1903 (and telegraph faxes much earlier), but it wasn't considered a useful technology until the 1970s.
posted by Sidhedevil at 10:14 AM on June 10, 2012 [2 favorites]

scunning, the Wikipedia article is actually pretty accurate. Rolled plate glass made glass windows widely affordable.
posted by Sidhedevil at 10:16 AM on June 10, 2012 [4 favorites]

Glass isn't actually essential for letting light in through a sealed window: in grade school I was taught that in the American colonial and post-colonial era, oiled paper was used and I would assume that pre-paper a vellum-type material would work as well.
posted by XMLicious at 10:16 AM on June 10, 2012 [2 favorites]

valkyryn -- I learn more things from Metafilter than I think I do anywhere else. Wasn't expecting you to tell me that the heavy-glass-at-the-bottom-flowing-glass theory was actually a myth. I first heard that when I was in Italy 15 years ago, and it was accompanied by someone using that as evidence to tell me that glass was a liquid and not a solid. I just assumed that regardless of its state, the glass was flowing down because of gravity. I didn't realize it had to do with the process itself.

Right -- blowing glass. That seems like what you would expect in this universe. That is a process that I could imagine a blacksmith doing as its a method of using heat and ore and shaping in the fire. Glass panes, I guess you're saying, must have become more common in houses and buildings because they replaced that blowing process with something else in the Industrial Revolution?
posted by scunning at 10:17 AM on June 10, 2012

There's a ton of stained glass in the Red Keep in the TV show, and I'd swear that there was mention of a stained glass window in a small sept where Catelyn prays for her children after Ned's unfortunate incident in the books.
posted by BrashTech at 10:18 AM on June 10, 2012 [2 favorites]

Glass trinkets are relatively easy to make and don't really have any bearing on the availability of glazing. Making clear and flat glass is far harder, and making large pieces is technically demanding. In medieval times even wealthy houses would only have windows made from small panes leaded together. Poorer houses ad shutters and were dark and smoky, although also pretty drafty. Glazing didn't become common until the 1600s or so in England, and maybe into the 1800s for the poorest and rural.

You should be rightly impressed with Gothic cathedrals that have huge glass windows. Glazing was a massive investment in itself, and not just to "fill a hole", so to speak.
posted by Jehan at 10:18 AM on June 10, 2012 [1 favorite]

But that's more small pieces, not large panes.
posted by BrashTech at 10:18 AM on June 10, 2012

Plate glass is hard to make in sufficiently large sheets to do windows. Premodern glass windows are often tesselated affairs as mentioned up thread, and it's very, very difficult to get a glass bubble big enough to spin out into glass. There's also the question of getting the right mineral blends. Any old sand mixture isn't going to produce the right degree of clarity, There's nothing at all to say that the glass objects aren't trade goods, small portable things brought from over the narrow sea from lands that have the right compounds and the skills to make good glass.

More on glass production here:
posted by Jilder at 10:19 AM on June 10, 2012 [2 favorites]

Sidhedevil -- ahh, "architectural glass". That would be the right thing to search for on Wikipedia. Thanks. Between this article and the comments on here, I am getting a better understanding about why it may not have been something we saw in the pre-modern era (which if anything GoT appears to be that).
posted by scunning at 10:19 AM on June 10, 2012

Why is that?

I'm guessing simply due to the lack of economic infrastructure. Again, glass is a relatively expensive manufactured material compared to wood or stone.

But that aside, technological development is a chaotic, erratic, unpredictable process. Why was it that no one really perfected calculus until the seventeenth century, but then two or three people perfected it at almost the same time? Many of the components were already there in the ancient period, but for reasons no one understands, it just didn't come together.

Why was John Deere the first person to invent a steel plow? The Romans had plows. The Romans had steel. Why did it take until the mid-nineteenth century for that to happen? It's just one of those things.
posted by valkyryn at 10:20 AM on June 10, 2012 [1 favorite]

I'd swear that there was mention of a stained glass window in a small sept where Catelyn prays for her children

That would be analogous to Europe in the era of the War of the Roses---some magnificent stained glass windows were made in the 15th century.
posted by Sidhedevil at 10:22 AM on June 10, 2012

So, just to help me frame this in my mind, when this plate glass method becomes available, what value are the 17th century architects and others seeing at the time? They are thinking about how it might impact insulation or aesthetics, or some such?

Why even have windows at all before glass panes (I'm sure it's obvious, but I wanted to ask the more informed so I don't have to speculate)? It seems like windows would help with circulating the air, but doesn't it also make construction more difficult (having to cut out those additional panes maybe takes more time and materials?). Plus won't the homes fill with insects or is that not really the case?
posted by scunning at 10:23 AM on June 10, 2012

It sort of depends on what you consider the equivalent time frame between Westeros history and our history, but given certain technologies shown in GoT, glass windows would have been possible if maybe rare. Of course, plate glass wasn't going to happen back then, but obviously medieval cathedrals have windows. Laon Cathedral's rose window dates from 1210, which seems consonant with the general architectural style of GoT. Major complex castles started happening around the same time.

Small glass pieces for stained glass windows would definitely be possible for GoT, but probably not large panes.
posted by LionIndex at 10:23 AM on June 10, 2012 [1 favorite]

Any old sand mixture isn't going to produce the right degree of clarity

This is also key. Just because you've got sand doesn't mean you can make glass worth having. The sand you find naturally isn't just sand, but stand with bits in it. Calcium carbonate, vegetable matter, diatoms, salt, you name it. The idea that a particular region might not develop a glassmaking industry because their sand has the wrong bits in it is pretty plausible.

And when you think about it, the only way you'd even know that is by taking a bunch of samples and trying it out. And getting the industry up and running means carting large amounts of sand around. Sand, being basically just teeny rocks, is heavy, and transportation isn't free.
posted by valkyryn at 10:23 AM on June 10, 2012 [2 favorites]

On the issue of bugs, people didn't know or understand that they were vectors for disease until much later. They were annoying, but nothing to worry about.
posted by Jehan at 10:24 AM on June 10, 2012 [1 favorite]

Plus won't the homes fill with insects or is that not really the case?

I would guess that your average medieval person who rarely took a bath wasn't quite so concerned about insect intrusion, and probably had little knowledge of the spread of disease by insects. Also, most mosquito-borne illnesses aren't really an issue at European latitudes.
posted by LionIndex at 10:25 AM on June 10, 2012 [1 favorite]

valkyryn -- part of your chronological explanations seem to be pointing to what happened with the Industrial Revolution. That brought costs down a lot, I think, and shifted the capital to labor input mix for a lot of production methods. Labor and capital both became much more productive during that period. So I wonder if maybe something like pane glass required that kind of economic shift. If most of the costs are bound up in the labor materials, and even then the methods do not really have economies of scale so that you can make large panes just as easily (though with proportional increases in inputs), then I'm thinking part of the reason is economic and not merely scientific. That doesn't explain the calculus anecdote that you bring up -- the development of science and so on -- but maybe it gets at why you aren't seeing this in buildings til later. You need a method that has technical economies of scale, and even then it may not be affordable if the time it takes to make a single, stable pane of glass is long. Then you're just stuck unable to actually build buildings that economically could have these kinds of things. (I'm just thinking out loud).
posted by scunning at 10:27 AM on June 10, 2012

Scunning, the book you want to read is Glass: A World History. It will answer most of the questions you're asking and give you a wider historical context, as well as being a cracking good read.
posted by Mizu at 10:29 AM on June 10, 2012 [12 favorites]

I visited Gravensteen castle in Ghent, Belgium last month and their windows struck me as really beautiful. I took lots of pictures of them and wonder if they might be helpful in thinking about this. Unfortunately I don't know why they are like that or even if the windows are original to the 12th century castle.
posted by misskaz at 10:32 AM on June 10, 2012 [1 favorite]

I think another thing to consider is the fact windows may have been at one stage a case of conspicuous consumption. Peasant homes would have had small windows for light and air, assuming it was good enough weather to open them. Wealthier homes would sometimes show off with how much glazing they could afford, see Wollaton Hall and Little Moreton Hall.
Also, most mosquito-borne illnesses aren't really an issue at European latitudes.
Actually, malaria was common in some parts of England far into the 1800s. It was only the draining of wetlands that finally wiped out malaria, not the climate.
posted by Jehan at 10:33 AM on June 10, 2012

In the book, I believe Winterfell had a glass room/greenhouse type place for plants to grow, which had large panels of glass. I assumed this was just their 'alternate world' possibility. And would imagine that couldn't exist in our world.
posted by Vaike at 10:34 AM on June 10, 2012 [6 favorites]

Also, see Hardwick Hall for conspicuous consumption of glazing.
posted by Jehan at 10:38 AM on June 10, 2012

An interesting note: at least in Hawaii, volcanic glass can apparently naturally form into translucent sheets. So as long as it's a completely fictional world anyways you could also posit an accessible trade source for this instead of technologically-produced glass, at least for mullion/leaded windows.
posted by XMLicious at 10:39 AM on June 10, 2012

For the record, the Industrial Revolution didn't begin until the mid-18th century. Sidhedevil's cite about when glass windows became common occurred about a century earlier than the Industrial Revolution, in the 1600s, or the 17th century.
posted by lilac girl at 10:57 AM on June 10, 2012 [2 favorites]

lilac girl -- Good point. I got my dates mixed up. I think there are some ideas that predate the IR, but the massive increases in income per capita really do not begin until the mid-1700s (Figure 1).
posted by scunning at 11:08 AM on June 10, 2012

Though it does seem like the Industrial Revolution has a profound impact on production of glass -- here and here. Interestingly, the glass bottle for beer was one of the things the Industrial Revolution brought about. (Even more relevant for GoT).
posted by scunning at 11:11 AM on June 10, 2012

Also a consideration with whether or not to glaze your windows in a Game of Thrones like environment would be the neccesity of being able to shoot out of them?
posted by ThisIsNotMe at 11:17 AM on June 10, 2012 [3 favorites]

Also, even if you could MAKE big panes of glass, the problem becomes how to transport them. Remember the state of the roads in GOT -- how long do you think a big pane of glass is going to survive in an ox-cart?
posted by KathrynT at 11:22 AM on June 10, 2012 [2 favorites]

I imagine it's just easier to light and shoot sets when the windows have no glass in them to stop reflections of the crew etc

This is not really a factor.

Now, it could be that the UPM decided to skimp the budget by convincing the art department that, based on the world of the show, they didn't entirely need glass.

But still, I imagine it's a stylistic choice and not subject to the demands of the production.
posted by Sara C. at 11:33 AM on June 10, 2012

I would guess that your average medieval person who rarely took a bath

I've read that medieval folk actually bathed pretty regularly, in group baths a la the Romans; it wasn't until the early Renaissance (after the Plague?) that bathing went out of fashion in some places. Perhaps a more informed person could elaborate or correct me.

Also, GoT sort of resets the War of the Roses in, as one wag on this board put it, not McEurope, but McByzantium. Byzantium had stained glass, of course, but were plate glass windows common there?
posted by Sticherbeast at 11:39 AM on June 10, 2012 [1 favorite]

If you're curious about building history in general, in addition to glass, Bill Bryson's At Home: A Short History of Private Life traces the history of what homes looked like and how they were used, with all sort of other interesting digressions. For instance, upholstered furniture was a consequence of the creation of the concept of a dedicated dining room. I know there's some info in there about blows vs. plate glass, and also the enormous greenhouse that was created for the London World's Fair.
posted by duien at 2:38 PM on June 10, 2012 [5 favorites]

My understanding is that in the middle ages, glass windows were a luxury due to the difficulty and expense of making large, flat pieces of glass as opposed to small trinkets and lamps and vases and such (though even these were fairly precious compared to today, especially for larger objects). Also, not everywhere had a local glassmaking industry, and some areas of the world were definitely more skilled at glassmaking than others.

In GoT, glass is often referred to as "Myrish glass", implying that it is usually imported to the Seven Kingdoms rather than made there, which would make it even more spendy. So you'd only see glass windows in the homes/buildings of particularly wealthy people/organizations, and even then it would often be used sparingly unless one were making a conspicuous display of wealth. This seems to be borne out in the books/shows and seems plausible enough to me.
posted by Scientist at 3:22 PM on June 10, 2012 [2 favorites]

I wouldn't be surprised to find glass windows in some wealthy homes/palaces in Game of Thrones. But you could certainly do Winterfell with wooden shutters or something to keep out the winter.
posted by J. Wilson at 3:57 PM on June 10, 2012

Why even have windows at all before glass panes

Since it hasn't been mentioned, there are other things one can put in a window that will allow at least some light and will keep out at least some drafts, such as oiled paper, scraped thin animal skins or membranes, fabric, etc. The need for light, ventilation, and all the other regular window functions existed long before glass.
posted by Forktine at 5:31 PM on June 10, 2012

People had windows for light and fresh air. As Forktine said, they used animal vellum and/or paper and/or wooden slat thingies ("Venetian blinds" are called that for a reason) and/or horn, depending where you were. A house without windows would have no ventilation, no natural light (most light sources--yes, even candles!--were costly until around the time that glass windows were readily available), and nothing to throw your chamberpot out of.
posted by Sidhedevil at 6:41 PM on June 10, 2012 [1 favorite]

I just finished reading the last book and one of the characters wishes he had the glass for a greenhouse, like the castle he grew up in did. But he muses that glass must be shipped from Myr (one of the Free Cities across the sea) at great cost. So from that, I'd guess that in the world of GOT, glass is quite rare and expensive - you can have trinkets, but not whole windows.
posted by lunasol at 6:44 PM on June 10, 2012 [2 favorites]

Another thought: for the TV show, not having glass windows might be an intentional choice by the set designers, as having glass windows would make the world look too modern or clean. Even though glass window panes might realistically exist in the nicer castles, it's not a good idea to have them if they'll take the viewer out of the show.
posted by Sticherbeast at 7:12 PM on June 10, 2012 [1 favorite]

In GoT, glass is often referred to as "Myrish glass", implying that it is usually imported to the Seven Kingdoms rather than made there, which would make it even more spendy. So you'd only see glass windows in the homes/buildings of particularly wealthy people/organizations, and even then it would often be used sparingly unless one were making a conspicuous display of wealth. This seems to be borne out in the books/shows and seems plausible enough to me.

It's important to remember that Westeros is a fallen civilization, dating from after the time of the Doom of Valyria. If you'll recall - the magics and bindings on the Wall are no longer fully understood. With the fall of magic, items traditionally produced with or involving magic fell sharply - such as why the glass candles no longer produce light for those attempting to finish their chain.

With a magic-based production source, there would be less need to have sought non-magical means of running their civilization. Then when it began to disappear, they were stuck to figure this out.

Another thing to remember is that the seasons in the Game of Thrones are quite hard. Winter in the North is bitter cold-glass windows would be useless, and bugs don't tend to fly about in the cold. They want more effective ways of keeping heat in.

I mean, um...geek off.
posted by corb at 8:03 PM on June 10, 2012 [4 favorites]

I recently read a book about the history of the house as we know it (At Home by Bill Bryson) in which he discusses how one of the great wonders of the Victorian era was simply a giant empty building made of glass because glass was so *expensive* to produce at that time that people had never seen it used in such a large scale. While windows as openings into the outside world existed from almost the beginning of houses themselves, glass wasn't used to cover them - unless you were quite wealthy - until the Industrial Revolution.

Glass as a technology was absolutely feasible, but the use of glass for trinkets and not for large scale uses like windows absolutely makes sense historically considering how expensive it was to manufacture.
posted by sonika at 4:58 AM on June 11, 2012

I suspect our logic is off on this too. If you're burning animal fat or timber for your light and cooking, especially in the long summer in which the show is set, keeping a room breathable is going to be important. Open windows without glass are going to prevent disease, rather than allow it in, by providing fresh, clean air, with significantly less soot and other pollutants.
posted by Jilder at 5:42 AM on June 11, 2012 [2 favorites]

Pre-columbian mesoamericans understood the wheel, but was just a toy to them as they didn't have much use for it (not enough large and powerful beasts of burden and too much free slave labor).

Of course, we're talking about a universe here where sorcery is literally real, so there's probably a plethora of ways you can insert glass into it logically. Or you can be handwavey and say that the materials they used to make glass aren't our materials and glass can't be bigger than a couple of inches without collapsing on itself.
posted by damn dirty ape at 6:26 PM on June 11, 2012

In the semi-biographical Little House on the Prairie, real glass exists but Pa Ingalls builds a log cabin using greased paper for the windows: it lets light in and keeps bugs out, and real glass is too expensive. In the ASOIAF world, glass similarly exists but may be too difficult to make as a hardware supply and not fancy jewelry.
posted by nicebookrack at 7:46 AM on June 13, 2012

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