Glassblowing and Sand Quarrying: Resources sought

[Rosemary Tea]

I'm looking for some solid information on glassblowing and sand quarrying, at the level of technology available prior to the industrial revolution. I have a wip that includes a glassblower and his employees (apprentices and journeymen) and the nearby sand quarry where they're getting their raw materials. Trying to make it as accurate as possible.

Google searching has given me a general overview, but I can't find answers to my specific questions:

- What would a pre-modern sand quarry look like? How big would it be? The images I've found are all of contemporary quarries. I expect it would look rather different if it hasn't been shaped by modern machinery.

- Who would do the quarrying? The glassblowers themselves? Or would it be a separate operation? I imagine quarrying sand would be a laborers' job, while glassblowing is a highly specialized skill. I would think the glassblowers would be entirely focused on the glassblowing part of it, and let less specialized laborers supply the raw material. But, if it's a small operation, might they do their own quarrying, maybe in the off season? Which brings up the next question....

- One source I found online said glassblowers stopped working in the summer because it was too hot. Makes sense, in the absence of modern cooling systems. But I can't find anything to back that up. Googling "summer glassblowing" or any variant thereof mainly brings up summer glassblowing workshops at various rec centers and day camps. The way I've written the story so far, the glassblowing shop is operating when certain events are taking place, which the glassblower's apprentice plays a key part in, and other parameters of the story require those events to be taking place in the summer. It would be trickier to write if the glassblower closes the shop at that time.

- By the same token, would quarrying take place year round, or just seasonally? The climate where my story is set is mildly four season: summers get hot, but the mercury won't break 100 (Fahrenheit) unless there's an extreme heat wave. Winters see a little snow, but not a pileup of it, there's more frost and rain than there is snow. I've imagined, so far, that there would be no quarrying in the winter if it's icy. Plus, I don't envision there being permanent housing for the laborers, assuming laborers are doing the work, anywhere near the quarry. Rather, they set up a seasonal camp.

Would appreciate any information and any resources.

 

[Prince of Spires]

I'm no expert on glass and I (unfortunately) don't have time to dive into this research rabit hole. But I might be able to give you a direction you can search in. In Europe, Venice was the premier glass manufacturer for a large part of the pre-modern era. A search like "glass blowing Venice renaissance" gives a ton on history on the subject (this is an interesting one: History and Evolution of Glass Blowing (mountainglass.com) not so much because of the page itself but because of the links at the bottom of the page).

Some thoughts: It depends a bit on the scale of the operation how much is done by different groups of people. But I think the glass blowers wouldn't do the quarying themselves. In Venice, they certainly didn't (all materials were imported). But also, glass blowing is a highly technical skill, with expensive output. As a glass blower it makes no sense to spend an hour quarrying for raw materials when you could simply pay someone minimum wage to do it for you while you actually create something fit for a king (and priced accordingly). There are several raw materials needed. It's unlikely that all of them are in the same spot, so you'll have some trade. But even if they are, a highly skilled glass blower is not going to spend 3 days in 3 different quarries to get all the materials while he could make someone less skilled do it for him.

I also doubt an aprentice would do it. It's not a skill related to glass blowing, so it doesn't help you in becoming a master. An apprentice might go to a quarry a couple of times to get an idea of the materials he's working with and how to get them and such. But I don't think he would spend a lot of time on it. Now, processing the raw materials is different. I can definitely see an apprentice crushing rocks to the right size and mixing stuff.

Seasonality depends on your location. I think the earliest glass blowing was found in egypt and the middle east (with the phoenicians doing lots of it). And I can see it being too hot to work inside a workshop with fire in the middle of a desert. Anywhere else, not so much. I think the glass blowers of Venice weren't even alowed off their island for some parts of their history. I doubt they would be stuck on there for a whole summer and not work at all.

By the same token, the quarrying would be a most of the year operation. If the ground is inaccessible because of frost, snow or very heavy rain, then the quarry would probably be closed. Otherwise, I don't think it would shut down because of a season. Modern work and safety regularions weren't a thing in the middle ages.

I think you should consider the scale of your glass blowing operation. The larger it is, the more industrialized the process will be. As in, if it's one master and an aprentice out in the middle of nowhere, they will do a lot of the work themselves. But once you grow a bit bigger, you will see a lot of specialization, simply because it's more efficient and more profitable that way.

 

[Mad Swede]

OK, you don't quarry sand as such, you dig it out of a pit or off a beach. You'd need to think a bit about your geography and geology, because most sand is found in glacial moraines, or around rivers, lakes and the sea. Digging will be by hand, transport by horse and cart. Given the level of technology it won't be a very big sand pit, and it can't be very deep for fear of the sides falling in. Provided the sand doesn't freeze too hard you'll be able to dig it all year round. The owners of the pit may not just be selling sand to the glass makers, if the locals know how to make mortar then some of the sand may be used in building things such as castles. You'll also need to think where the fuel for your glass smelting is coming from. You can use charcoal, but coal would be better.

The climate you're assuming will allow glass making all year round. However, you'd need to be careful when you take glass out of the warm building into the frosty air outside, the glass will need to be wrapped. Glass blowing is a highly skilled craft, and your craftsmen will have a permanent place for their work. They may travel around to sell glass items, but they're likely to blow glass all year round if the can. The glass items they produce won't be cheap.

 

[Rosemary Tea]

Many thanks Mad Swede and Prince of Spires !

Geography and geology: the surrounding terrain is mountainous, but the town where this takes place is in the valley/foothills. Glacial moraines are quite possible. It's a landlocked area, so no sea, but rivers and lakes, yes.

Size of operation: this town only has the one glassblowing shop, but there are other locales within a day's travel or so that also have glassblowing. The quarry (or sand pit) would be supplying them, too. I don't see this being a full on industrial scale operation, but it would be big enough for specialization. And yes, there probably are bricklayers around who are using mortar. So that answers my question: the glassblowers would not be doing the quarrying themselves.

 

[Insolent Lad]

You can use charcoal, but coal would be better..

Yes, I have the glass industry taking off in a city in one of my novels largely because of coal (they speak of 'coals of the earth' in the book), allowing more heat and stronger glass. Wine bottles was the big thing for them because the country had a thriving wine industry!

 

[Rosemary Tea]

Seasonality depends on your location. I think the earliest glass blowing was found in egypt and the middle east (with the phoenicians doing lots of it). And I can see it being too hot to work inside a workshop with fire in the middle of a desert. Anywhere else, not so much. I think the glass blowers of Venice weren't even alowed off their island for some parts of their history. I doubt they would be stuck on there for a whole summer and not work at all.

Actually, here's what Wikipedia says about the glassblowers of Murano...

They did not work during the hot summer, during which furnace repair and maintenance was performed.[18] During the 1300s, the annual summer vacation lasted five months.[19] In the 1400s, the Venetian government shortened the summer vacation to three and a half months.[20] Murano glassmakers sometimes complained they were not working enough.

Now, my fictional glassblowers aren't under the level of regulation the Venetian glassblowers were, but at the very least, they would have to perform repair and maintenance on their furnace periodically. But then, who does the repair and maintenance? Would the glassblowers do it themselves, or would that take another area of expertise? Do they have to call in a repairman?

If they perform their own furnace maintenance, that solves my problem. I can have the glassblower close the shop for maintenance, for maybe a few weeks to a month, but the employees would stick around to help with the maintenance. They'd still be working, just not doing the usual.

 

[Rosemary Tea]

One more question, if anyone has any idea: if this sand pit is a big enough operation to be supplying several glassblowers and bricklayers, how many laborers would it be likely to employ?

Thinking of a scene where characters go to the sand pit and see the laborers at work. Might there be half a dozen of them? A dozen? More?

And I would think there would be a foreman or two, to keep an eye on things?

 

[skip.knox]

It would really be as big as you care to make it. I know that isn't much help, but it is so. The sand in an area might be worked only occasionally, by ad hoc hirelings. Or it might be a full-time, large-scale operation.

If it is a permanent operation, there would certainly be a supervisor, simply because the sand pit itself is a commercial operation. There would be the owner but also a supervisor. Here I follow medieval conventions where natural resources are owned by the nobility and are farmed out to others. The supervisor and at least some crew would be resident, so either there's a pit village, or there's a regular farming village nearby where the crew lives. There will also be carters, for the sand must not only be collected, it must be transported. Those are typically hired by the site. In a big operation, at least some of these would be resident as well. And once you have a community, you'll have ancillary trades such as a carpenter/wheelwright, a smith, and so on. There would also be a market nearby, for this community is far from self-sufficient.

 

[Rosemary Tea]

It would really be as big as you care to make it. I know that isn't much help, but it is so. The sand in an area might be worked only occasionally, by ad hoc hirelings. Or it might be a full-time, large-scale operation.

Hmmm... I've already placed it near a village that isn't built around quarrying or glassblowing. So maybe it's a pretty small operation. The one glassblower is there because there's a decent source of raw materials nearby, and enough of a market he can sell to (some local, some shipped off), and since he's been employing several apprentices and journeymen, it looks like he wants to expand. But for now, it's not a big thing.

I suppose whoever owns the sand pit could be running a small operation but looking to expand it, too. Which would fit with some of the details I have in mind.

 

[skip.knox]

Oh, it could still be large, though it doesn't need to be.
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A single glassblower would be unusual. There's a big capital investment, and it's highly unlikely you'd have enough customers locally, which means somehow having regional or international trade connections. You tend to find glassblowers working in groups.

But there's a magical way around this. Maybe this glassblower can produce specialty items, and the local sand has special properties. Or there are other raw materials that provide the magical spark (it's never *just* about the sand).

The expanding angle works, regardless. A common business arrangement was for some enterprising individual, often a merchant, loans money to a cash-strapped noble. The loan gets repaid by letting the merchant exploit a natural resource for some fixed period of time. The merchant figures not only to make back the loan but to make a profit, so he's motivated to work the resource intensively. That would include expanding excavation, adding new markets, or increasing efficiency.

 

[Rosemary Tea]

A single glassblower would be unusual. There's a big capital investment, and it's highly unlikely you'd have enough customers locally, which means somehow having regional or international trade connections. You tend to find glassblowers working in groups.

Would that be so even if glassblowing were a fairly new industry in town? Say, if one family had started it and it's still in the first generation. The glassblower might have learned the trade somewhere else, taken a trip down this way, found that there's this marvelous sand source nearby, and decided to set up shop... with no local competition.

Perhaps this glassblower came from a family of glassblowers that had amassed some serious wealth. That way, he could have afforded the expense of creating a new shop before he started making profits of his own.

But there's a magical way around this. Maybe this glassblower can produce specialty items, and the local sand has special properties. Or there are other raw materials that provide the magical spark (it's never *just* about the sand).

That actually works very well with my setting. The presence of the glassblower in the story came about because of a rivalry between the glassblower's apprentice and the mage's apprentice, which all started when the glassblower's apprentice, who is very full of himself, said, "You think you can do magic? Glassblowing is the real thing!" and kept bragging about it again and again. Which brought some "oh, yeah, we'll see about that!" from the apprentice mage, who's rather cocky herself.

If there's a bit more magic involved in the glass making, that opens the door to a steady business arrangement between the glassblower and the mage, which would ensure that their apprentices know each other. Initially, I had them meet through mutual friends, other trades' apprentices, who were all at the same hangout spot on their day off.

That also provides a neat explanation why there's a mage and a glassblower both living on the same end of town. I'm already saying that mages live on land that's especially magical - has ley line convergences on it. The sand pit isn't on the mage's land, but it's not very far away. So, is the sand magical? Probably....

 

[ButlerianHeretic]

While charcoal tends to burn a lot of trees, if there are peat marshes in the area, then peat can be compacted into briquettes, dried, and used to make charcoal. That would tend to be another industry, but they could be supplying bloomeries and smithies and the like too, maybe also potters and tile-makers. I would imagine that the glassblower might take advantage of this infrastructure of folks making fire-brick and constructing furnaces. Such industries tend to come to the source of the fuel since so much is needed, rather than the source of the raw materials. So it could be a town with a lot of furnaces thanks to other industries, that just happens to have a source of good quality sand that the glassblower can take advantage of.

While I don't know about information on period glassblowing, there are lots of videos of folks making primitive bloomeries on YT that might give you some ideas, and one of the later episodes of the Timeline series features a tile-making kiln. That said, those tend to be batch processes iirc, while a glassblower would not, so I don't know how useful those would be.

 

[Mad Swede]

One more question, if anyone has any idea: if this sand pit is a big enough operation to be supplying several glassblowers and bricklayers, how many laborers would it be likely to employ?

Thinking of a scene where characters go to the sand pit and see the laborers at work. Might there be half a dozen of them? A dozen? More?

And I would think there would be a foreman or two, to keep an eye on things?

This depends a bit on your setting.

In a rural economy (pre-industrial revolution) a sand pit like that might be run as a cooperative by several farmers, or it might be run by one farmer. Either way, they'd only be digging sand when they didn't have anything else to do, like ploughing or harvesting grains. So it would be a mainly winter activity, with only some part time work at other times of year. The farm labourers (if the farmer has them) would probably help in the pit when there was nothing else to do on the farm. So at most you'd be talking about 4 or 5 people, and the farmer would use his horses and carts to transport the sand.

If the local economy is large enough to support year round operation of the sand pit, then yes you would have 4 or 5 labourers and a foreman. You'd also have a load of carters with horses, who might be independent or who might also be employed by the owner of the sand pit.

 

[Rosemary Tea]

This depends a bit on your setting.

In a rural economy (pre-industrial revolution) a sand pit like that might be run as a cooperative by several farmers, or it might be run by one farmer. Either way, they'd only be digging sand when they didn't have anything else to do, like ploughing or harvesting grains. So it would be a mainly winter activity, with only some part time work at other times of year. The farm labourers (if the farmer has them) would probably help in the pit when there was nothing else to do on the farm. So at most you'd be talking about 4 or 5 people, and the farmer would use his horses and carts to transport the sand.

If the local economy is large enough to support year round operation of the sand pit, then yes you would have 4 or 5 labourers and a foreman. You'd also have a load of carters with horses, who might be independent or who might also be employed by the owner of the sand pit.

Thanks so much! Exactly what I was looking for, and this helps me a lot with building the story.

 

[Rosemary Tea]

While charcoal tends to burn a lot of trees, if there are peat marshes in the area, then peat can be compacted into briquettes, dried, and used to make charcoal. That would tend to be another industry, but they could be supplying bloomeries and smithies and the like too, maybe also potters and tile-makers. I would imagine that the glassblower might take advantage of this infrastructure of folks making fire-brick and constructing furnaces. Such industries tend to come to the source of the fuel since so much is needed, rather than the source of the raw materials. So it could be a town with a lot of furnaces thanks to other industries, that just happens to have a source of good quality sand that the glassblower can take advantage of.

While I don't know about information on period glassblowing, there are lots of videos of folks making primitive bloomeries on YT that might give you some ideas, and one of the later episodes of the Timeline series features a tile-making kiln. That said, those tend to be batch processes iirc, while a glassblower would not, so I don't know how useful those would be.

I've already got the fuel accounted for. At least enough to not make readers say, "Wait a minute, that's impossible!" I suppose a brief mention of the other resources nearby could come up if someone tells the backstory on the glassblower. Something about how he started a business here because there were good resources, an untapped market, something like that.

 

[skip.knox]

Magic sand might reduce the fuel requirement. Maybe.

 

[Rosemary Tea]

Magic sand might reduce the fuel requirement. Maybe.

My working premise is that magic has made a more sophisticated form of fuel available, without the problems with resource depletion and air pollution that most current and past fuels have incurred, but at a level of technology that would not be impossible at a pre-industrial level. Fuel sources like wood or peat might be used in out of the way places that don't have the infrastructure for magical fuel, but towns and cities and even some rural spots do have it (it's more touch and go in the rural areas, though).

Magic. You can count on it for anything.