Glass in Cerilia

[Ariadne]

One of my characters wants to create a magical mirror (when ready, I'll post it here). My question is: How common is glass in Cerilia (my character lives in Khinasi).

IMO glass should be less expensive, where natural sodium and potassium carbonate exists. In the old Egypt where (and are) natural seas of sodium carbonate (potassium carbonate is created through burning wood). That's why glass is known there very early. Are such natural seas found in Khinasi (or elsewhere in Cerilia)?

Next question: Mirrors are created with a reduction of a silver salt today. Some (cheap) ideas of creating mirrors in Cerilia?

Please comments...

[geeman]

At 02:42 PM 1/6/2003 +0100, Ariadne wrote:

>How common is glass in Cerilia (my character lives in Khinasi).
>
>IMO glass should be less expensive, where natural sodium and potassium
>carbonate exists. In the old Egypt where (and are) natural seas of sodium
>carbonate (potassium carbonate is created through burning wood). That`s
>why glass is known there very early. Are such natural seas found in
>Khinasi (or elsewhere in Cerilia)?
>
>Next question: Mirrors are created with a reduction of a silver salt
>today. Some (cheap) ideas of creating mirrors in Cerilia?

Second question first: Tin, lead and mercury were all used as alternate
metals in mirrors. Lead and mercury, we now know, aren`t the safest
household items, but tin will work. There`s always polished metal (usually
bronze or silver) as a reflective surface. Given the actual amount of
silver used to back a mirror, though, the cost of the material probably
isn`t going to be that dramatic an influence.

The materials needed to produce glass are pretty common, and the basic
process relatively simple. The question of cost is probably more
accurately reflected by considering the scale and scope of manufacturing
glass rather than access to the components. In Khinasi there could and
likely would be small, glass making "shops" and trade organizations,
particularly in the larger, urban centers. Costs should be based on the
size of the glass with larger pieces, of course, being more
expensive. Quality is also an issue, but without some sort of magical aid
(which there probably would be even in a low magic setting like Cerilia)
the methods used in later middle age/early Renaissance glass manufacture
were fairly standard, so the quality of the glass will depend on the skill
of the craftsman.

The PHB prices a small, steel mirror at 10gp. In general the prices for
upgrading materials in 3e run from x2 to x10 of a "base" item, so a
similarly sized glass mirror might be 50gp. Sizing the mirror up would
probably cost dramatically more, however. Closer to the x10 price increase
per size category. (They probably didn`t mean "small mirror" in to mean it
was sized small when they penned the 3e materials--it`s most likely just a
holdover from previous editions--but since it seems to fit so nicely into a
simple math formula I`ll go with it.) A sized medium glass mirror,
therefore, might cost 10 x 5 x 10 = 500gp. Note that`s size medium for an
item which probably makes that mirror about 2` x 3`. A full length mirror
would be size large and cost 5,000gp using that formula.

Hope that helps.

Gary

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[Azrai]

Originally posted by geeman
The materials needed to produce glass are pretty common


I don't think these materials are common.Glass was a very precious material in middle-age. Natural sodium and potassium carbonate could not be found in every region.

[Arjan]

I suggest using indeed bronze or silver?
The mirrors used in Greco-Roman were made of silver.

hope this helps

A.

[geeman]

At 07:45 PM 1/6/2003 +0100, Azrai wrote:

>I don`t think these materials are common.Glass was a very precious
>material in middle-age. Natural sodium and potassium carbonate could not
>be found in every region.

Burn an organic compound (usually wood) and you get potassium
carbonate. Historically it`s called potash or pearl ash since its the
glossy white powder at the bottom of the vessel the material is "cooked"
in. Similarly, burning kelp is where glass makers got soda ash or sodium
carbonate for their glass recipes. Silica, of course, is abundant but
various "qualities" of sand have different characteristics.

Gary

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[Birthright-L]

If the mirror is for making a magical item, the cost of the mirror would
count against the ratherexhorbiant cost of creatinbg the magic item - so I
don`t see any problem with the mirror being expensive. In fact, it is in
many ways a merit, as it cuts down on the number of other rare/expensive
components that must be found.


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[Azrai]

Originally posted by geeman
Burn an organic compound (usually wood) and you get potassium
carbonate. Historically it`s called potash or pearl ash since its the
glossy white powder at the bottom of the vessel the material is "cooked"
in.


Yup, this is exactly what Ariadne pointed out. But the question was: do I find this resources in every region? For example wood could be a problem in Kinashi, since you need a very large ammount of creating potash. The natural resources are not trivial at all. In same places in Europe it has been a problem till the 18. century.

I think your price list is realistic, I would have guessed in the same direction.

[geeman]

At 01:08 AM 1/7/2003 +0100, you wrote:

>For example wood could be a problem in Kinashi, since you need a very
>large ammount of creating potash.

There are large forested areas of Khinasi. Sure, there wouldn`t be a glass
industry in the middle of the Tarvan Waste, but there`s very little there
anyway. When it comes to resources needed to create glass the problem
would probably be more the amount of wood or other fuel needed to heat the
kiln long enough to "blend" the components rather than the amount needed to
create potash. (In a fantasy campaign, of course, there are magical
solutions to this problem.) Kelp apparently can grow most anywhere in
coastal waters that are 150` deep or so, which again excludes the Tarvan
Waste I guess. Sand for silicates, of course, are available widely (the
one resource even in the Tarvan Waste has in abundance.)

It does require large quantities of wood to make glass. I don`t have any
information on how much wood, but I would guess it would be comparable to
the amount necessary to smelt ore, probably less considering the relative
size of such operations. Some sort of enchanted kiln, however, is a
distinct possibility in a world where magic exists, especially since in BR
we have a goddess of fire who loves people who create beautiful things
(like glassworks) and her priesthood could likely create such items.

Gary

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[Beruin]

Gary wrote:

>>It does require large quantities of wood to make glass. I don`t have any
information on how much wood, but I would guess it would be comparable to
the amount necessary to smelt ore, probably less considering the relative
size of such operations<<

I did some research on the quantities of wood required in pre-industrial production processes a while ago and can give some rough figures. A single glassmaker would require about 2.5 metric tons of potash a year. Depending on the woods used, this would require about 11 tons of wood. A single hectare of forest holds between 120 and 720 tons of wood, depending on the circumstances, with a yearly growth of somewhere between 1.3 and 9 tons.
I couldn`t find numbers detailing the amount of wood needed to smelt the glass, but in pre-industrial Germany both metal production and glassmaking were regarded as `Holzfresser` (`wood-eater`).
On average, about 18 tons of wood were required to produce a single ton of wrought iron. Copper was even more wood-consuming, requiring up to 270 tons of wood for a single ton of copper. These numbers are only rough estimates, as the amount of wood needed could vary widely depending on the quality of the ore and other circumstances.
Well, I guess these numbers help to explain why so much of Cerilia is deforested and why the elves are not overly fond of those wood-burning humans.
BTW, the glass industry in England was required by law to use coal instead of wood since 1635, as wood was apparently to valuable and becoming to scarce.

The glass produced in Venice was regarded to be of the best quality in medieval Europe. The Venetian glassmakers used the coastal plants of their a area to create high quality potash that produced clear glass. The `forest glass` produced in other areas was usually green and considered to be of a lesser quality. I believe something similiar to the Venetian glass industry would be suitable for Kinasi as well.

Mirrors usually were produced by adding a layer of mercury to a plate of glass, a hazardeous process for the workers.

Well, I hope this wasn`t too boring and can be of use too someone,

As an afterthought, you might want to check out the d20 supplement Spells&Magic, produced by Bastion press, which has a mirror mage prestige class and gives a description of the production process for creating mirrors. Basically, the process boils down to two craft (mirror) checks during different stages of the process, with a DC of 10 +1 per inch of diameter of the mirror.

Christoph Tiemann

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[Azrai]

Thank you Beruin for your interesting comment.

[geeman]

At 02:39 PM 1/7/2003 +0100, Christoph Tiemann wrote:

>I did some research on the quantities of wood required in pre-industrial
>production processes a while ago and can give some rough figures.

Great data, CT. What are your references?

Gary

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[Lee]

Just an aside....

In a message dated 1/7/03 8:41:11 AM Eastern Standard Time,
tiemach@UNI-MUENSTER.DE writes:

<< BTW, the glass industry in England was required by law to use coal instead
of wood since 1635, as wood was apparently to valuable and becoming to
scarce. >>

Probably to preserve forests for shipbuilding.

Lee.

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[ConjurerDragon]

Early mirrors are just highly polished steel or silver - no glass needed.
bye
Michael Romes

>Ariadne wrote:
> One of my characters wants to create a magical mirror (when ready, I`ll post it here). My question is: How common is glass in Cerilia (my character lives in Khinasi).
>IMO glass should be less expensive, where natural sodium and potassium carbonate exists. In the old Egypt where (and are) natural seas of sodium carbonate (potassium carbonate is created through burning wood). That`s why glass is known there very early. Are such natural seas found in Khinasi (or elsewhere in Cerilia)?
>Next question: Mirrors are created with a reduction of a silver salt today. Some (cheap) ideas of creating mirrors in Cerilia?
>

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[Beruin]

Gary wrote:
>>Great data, CT. What are your references?<<

I did a paper about mining operations and forest destruction in Siberia during the eighteenth Century nearly two years ago. The numbers I came up with are based on the account of the German explorer Johann Georgi who traveled Russia on the orders of the Czaress Catherine the Great. Georgi gave detailed descriptions of every mine and production facility he visited, including output, production processes and resources used. I extrapolated from this data, using other material for help.
Unfortunately, nearly all of the references I used are in German, with a smattering of French and English. I would be willing to mail my references to anyone still interested. For starters, I`d recommend the `Cambridge economic history of Europe`, volume 1 (middle ages) to 5 (early modern Europe) for English or American readers. I guess that this work will be available at most public libraries.
BTW, even though my references are not medieval, the production processes in Russia remained largely the same for centuries, so I believe that my data would be valid for Cerilia.

Lee Hanna wrote:
>>>
<< BTW, the glass industry in England was required by law to use coal instead
of wood since 1635, as wood was apparently to valuable and becoming to
scarce. >>

Probably to preserve forests for shipbuilding <<<

Yes, this was certainly one reason. In addition, large quantities of wood would be required to support the growing production of iron as it was not possibly to produce iron using coal until 1709 (the sulphurous fumes coal produces ruin the iron and other metals like copper as well) and it took nearly a century more until this technology was widespread.
In my campaign, the dwarves are the only race who have overcome these technological difficulties and who can use coal to produce high quality iron and other metals. It`s a closely guarded secret of their race. All other races have to use charcoal, i.e. wood.

With regard to shipbuilding, another historical example (Sorry, I`m a history buff ;-). In 1709, Czar Peter I forbid the felling of high quality trees like oaks in an area twenty miles wide on both sides of all rivers leading to Moscow upon pain of death to preserve the wood for his navy. Later, the sentence was lowered to cutting off the nose of the offender. Environmental decree, anyone?

Back to mirror making. I re-read the section about mirrors in the Spells&Magic supplement I mentioned. In addition to the two craft checks I mentioned, this book requires another two craft checks for creating the frame (DC between 6 and 30 depending on the size of the mirror) and the backing (depending on which material is used: no check for quicksilver; DC between 10 and 18 for copper, silver or gold; DC between 15 and 26 for Mithral or Adamantine once again influenced by size), an Alchemy (DC 15) and a craft check (DC 20) to seal the mirror. In addition, mirror mages can include magical fluids between glass and backing that shall increase the mirror`s magic potential. Doing so requires an Alchemy check (DC 5+10 per magical essence after the first) and an additional craft check (DC 20) to seal the fluid inside the mirror. The book lists 17 possible essences (for example Rose essence influences Force effects) that can be combined. Mirror mages can use their mirrors to store, reflect or absorb spells.

Well, sounds like an awful lot of skill checks to me, but since we`re speaking of magic items maybe that`s not too tough.

Christoph Tiemann

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[Ariadne]

Originally posted by ConjurerDragon

Early mirrors are just highly polished steel or silver - no glass needed.
May be, but I want to create something like the "Snow White" mirror and that is made of glass...

@Beruin: Thanks for your post...

[ConjurerDragon]

Ariadne wrote:

>This post was generated by the Birthright.net message forum.
> You can view the entire thread at: http://www.birthright.net/read.php?TID=1194
>
> Ariadne wrote:
>
Originally posted by ConjurerDragon
>
>Early mirrors are just highly polished steel or silver - no glass needed.
>May be, but I want to create something like the "Snow White" mirror and that is made of glass...
>
Sorry for my late post - I have to remember to read ALL posts that come
in before replying to one which had already been answered :-(

I can´t remember Schneewittchen (Snowwhite) so good to know of what
material the mirror was - perhaps it´s only in the movie? Or the author
simply used knowledge of his days to describe a mirror that at the time
of the fairy tale could not yet exist?

What I know definitely is that Perseus used a polished shield to defeat
the Gorgon Medusas petrifying gaze...
bye
Michael Romes

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[Beruin]

Quote:
>>Early mirrors are just highly polished steel or silver - no glass needed.<<

This is certainly true. The earliest mirrors are recorded for Egypt about 3000 B.C. They consisted of polished copper or bronze. However, glass mirrors existed in the Roman Empire since at least 300 AD. According to the Roman sage Pliny, the Phoenicians invented glass mirrors. These early mirrors produced a slightly distorted reflection as the glass was not polished. Apparently the technology was lost during the so-called `Dark Ages` and re-invented during the thirteenth century. Judging from the typical level of technology in Cerilia, glass mirrors would certainly be available and would probably be more common than polished metal.

(Reference: Peter James/Nick Thorpe, Ancient Inventions, New York 1994. A German translation under the title `Keilschrift, Kompass, Kaugummi` does exist)

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[Ariadne]

Originally posted by ConjurerDragon


I can´t remember Schneewittchen (Snowwhite) so good to know of what material the mirror was - perhaps it´s only in the movie? Or the author simply used knowledge of his days to describe a mirror that at the time of the fairy tale could not yet exist?
As I said already, I'll post it, when ready... ;)

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