In modern Japan, it’s a material used not only for tableware and windows, but as a base for many other applications. Nowadays it’s also difficult to crack it. At the same time, you might also say that it’s familiar and commonplace to a modern person.
However, in the past there were epochs where glass shone as a rare good equal to jewels and precious metals.
Large amounts of high-quality glass are directly manufactured by fusing the raw materials, silica sand and alkali, at high temperatures in the modern era. However, during the ancient times with its inferior science and technology, the production of glass was accompanied by huge troubles and efforts.
For that reason glass had been very expensive in the ancient times, and used as a substitute for jewels and precious metals.
And even on this Seldeas Continent, the production of glass is a hidden technology of the dwarves. In addition, the Holy Faith’s ostracism towards sub-humans has triggered a sharp decline in the number of dwarven glass craftsmen and a decrease of trade with dwarves, causing an intense glass shortage on the market which resulted in its rarity becoming even more prominent.
Coupling its rarity value with the beautiful ornaments created by dwarven hands, glass products were traded as very expensive, top-quality products used by only royalty and titled nobility.
As an outcome of Souma’s wish to develop a special industry in the city of Bolnis and Dvalin’s hope of reviving his race’s secret technology agreeing with each other, this dwarven glass workshop had been established.
But, the construction itself was accompanied by enormous hardships.
What was especially difficult was the production of the bricks used for the furnace and the crucibles for the sake of producing glass by melting the raw materials within. Not only did they need to endure high temperatures, the crucibles had to also withstand the melted glasses’ corrosive nature.
Such high temperature resistance material can’t be created by just baking clay. Not to mention the usage of carefully selected natural rock and clay, it also needed chamotte ― something that had been turned into powder by crushing heat-resisting bricks and pieces of crucibles.
And, fortunately the dwarves had those heat-resistant bricks and pieces of crucibles at hand.
Furnaces and crucibles, which can endure high temperatures without breaking apart during the manufacturing of glass and metals, are the lifelines of dwarves. The dwarves on the Seldeas Continent have the custom of carrying pieces of glass and heat resistance material of crucibles and bricks, which they made in their early days, as good luck charms in preparation for the times when they would lose their furnace or crucibles to unforeseen incidents.
Most dwarves lost them or had them stolen when they became slaves, but those who managed to hide little amounts, contributed their own shares of brick pieces and crucibles to create chamotte.
However, even for the dwarves this had been a bitter decision.
The bricks and glass are the crystallization of their family’s techniques which they continuously inherited, dating back to distant ancestors. Their ancestors had poured their everything into the family’s unique techniques, such as researching and developing additives and their blending ratio, while shedding tears of blood. Mixing those fruits of work with those of other families and homogenizing the various characteristics they had inherited is something they would have originally never allowed to happen as it results in no more than completely losing those inherited technologies.
But, Dvalin deliberately carried that out together with the following words:
“From now on we will become a new, single family.”
They were dwarves who gathered in Bolnis from all over the continent after suffering through various hardships. Hence, it was a decision for all of them to abandon their own families and create a new family under Souma.
Just that caused Dvalin to already feel deeply touched upon the glass workshop’s completion. However, he intently voiced out his worries in order to conceal his emotions.
“However, there’s still a long way to go. The used sand isn’t anything we can be satisfied with. Usually crystal waste or desert sand would be better, but…”
The reason for the deep green color of the jar passed to Souma is the iron portion in the used sand. Because of impurities such as other metals, glass has various colors. To create transparent glass, which is considered to be a top-quality product, one must strive to search for raw materials that don’t contain such impurities.
“Our side has taken measures in that regard. As soon as the sand arrives, I will have it brought here.”
Souma has asked Yoash, who seemingly got wind of the glass from somewhere and came to offer a deal, to obtain sand from various places. Especially the desert sand requested by Dvalin has to be ordered from the continent’s south that’s separated from the west through the Baness Bay. It was a blessing that they could gain Yoash’s cooperation on this as he possesses big proficiency in ocean trade.
“By the way, Sir Soma, I’d like to introduce the biggest contributor of this glass production to you.”
Dvalin calls for a nearby dwarf.
“This guy’s name is Knurl. He’s a brethren who hails from Holmea’s north.”
Souma, who clearly thought that he was one of the dwarves sold by the empire like Dvalin, asks Shyemul in surprise,
“Say, dwarves live around here?”
“Did you forget, Soma? This guy――” Shyemul taps the machete at her waist, “――is something my ancestor requested dwarves to make.”
Come to think of it, Zurgu said something along those lines when I first met Dvalin’s group, which I had bought off the slave dealer, together with Garam, Souma remembered.
“If I remember correctly, the dwarves, who lived in this area, disappeared after being driven out by the humans or such…”
Once Souma muttered to himself while recalling Shyemul’s words from back then, Knurl nodded deeply after hearing Souma’s mumbling.
“Yes. I’m one of the blood relatives of the dwarves who dwelt in the mountains around here in the past.”
“This guy provided a secret additive for the sake of making glass.”
Dvalin strongly emphasizes Knurl’s achievement.
“A secret additive for making glass…you say?”
“Indeed, Sir Soma. The glass production would have likely taken a lot more time without it.”
The secret additive is alkali which is added in order to lower silica sand’s melting point at the time of creating molten glass. In many cases the ash of burned plants was used as alkali on the Seldeas Continent. At first Dvalin intended to also use such ash, but the existence of Knurl’s additive changed that.
“There’s a deposit of trona.”
Trona is a mineral mainly consisting of sodium carbonate which can be found in the vicinity of large rivers and saline lakes. In Ancient Egypt it had been mined at the bottom of dried-up saline lakes.
After glancing at Shyemul, Knurl continued with a tinge of hesitation.
“During breaks in our machete trade with the zoan, we secretly mined trona at a deposit we discovered in the Solbiant Plains, and manufactured glass.”
Shyemul is surprised about something like that sleeping in the plains where the zoan live.
The trona deposit discovered by Knurl’s family is a big deposit of sodium carbonate which is still being mined on the Seldeas Continent of modern times.
This deposit is one where a large amount of ocean water was locked up on land in the past due to the shifting and clashing of continental plates, a process that formed the Dolnas Mountain Range which surrounds the Solbiant Plains. Some of the areas in the north turned into rock salt, but the ocean water, which got locked up in the center of the plains, turned into sodium carbonate ― trona through microbes and volcanic gases containing plenty of carbon dioxide surging up from the underground in a process of condensation.
“So, what’s your request to me?”
If I believe in Dvalin’s words, the achievements of this Knurl are tremendously big. Souma intended to go as far as doing something a bit unreasonable.
Knurl suddenly kneels in front of Souma.
“Please save my family.”
Knurl explained the current situation of his family to Souma who is confused about what he’s supposed to do due to the sudden request.
“Our families have been enslaved in the Malben Copper Mine by the humans of the country called Holmea.”
The Malben Copper Mine is located in the northern mountains of Holmea. The copper being mined there is said to provide the majority of the copper circulating not only within Holmea, but also the western continent. It’s a mine prided for its leading copper mining amount in the western regions.
However, originally it belonged to the families of Knurl and the others. Yet, around five years ago Holmea invaded with its military blaming the dwarves that they had sold them inferior copper, and occupied the mine together with the dwarven settlement.
Knurl continues to explain to Souma who’s surprised after being told about those particulars,
“Since then, we were forced to work in the mine as slaves. The men were forced to mine copper without rest everyday. If we went even a little bit against their orders, we were hit with sticks and whips. The provided food was little and there were no medicines either. For that reason many of my brethren have died from injuries and sickness. However, despite that we weren’t able to resist them because the women and children had been separately locked away as hostages.”
Knurl’s voice was filled with unconcealed rage and regret.
“During that time, I heard stories about this place here from the human jailers. I, who have been entrusted with the glimmer of hope for my clan, hid myself among my brethrens’ corpses, and escaped to this place by myself.”
Knurl pleads to Souma,
“Please…! Please save our clan!”
There are many cracks and cuts on the rough and bony fingers of his hands which he had crossed as if praying. Even his thick arms peeking out through his sleeves had traces of burns as if they had been pressed against soldering iron, and gashes from being lashed by whips.
Souma’s eyes soften due to his tragic state. But, after pursing his lips once, he told Knurl in a calm tone while choosing his words,
“Right now we have our hands full with protecting ourselves. We can’t go to war against Holmea in order to save your people.”
He feels sorry for Knurl and his clan, but that’s the real situation of Souma’s group.
Even if they might have defeated General Darius, Holmea still owns a military force of more than 20,000 soldiers. Souma’s group doesn’t hold the power enabling them to invade and fight off all those soldiers.
Due to his reply, not only Knurl’s face, but even the faces of Dvalin and the others show their disappointment.
However, Souma forced a smile on his sad face.
“But, the time to settle things with Holmea will come soon. At that time, it will most likely result in what you have requested.”
Knurl, who was overcome with emotions due to those words, shed tears of gratitude, and bowed so deeply that his forehead rubbed against the ground once more. Even the surrounding dwarves, who watched that, sniffled a bit.
“Watch us! We will produce the best glass and become your power, Sir Soma!”
As if to gloss over the tears gathering at the corners of his eyes, Dvalin laughed with a “Gahahaha!” while throwing out his burly chest.
However, suddenly there’s a murmur that seems to pour cold water on his declaration.
“How many forests are you going to destroy for that sake…?”
Souma was surprised by Eladia’s poisonous words.
As Eladia had apparently voiced that out unintentionally, she was only evasive at first when Souma asked what she meant. But, after Souma’s repeated questioning, she answered while choosing her words.
“To create this thing called glass, a large quantity of wood is used――,” Eladia surveyed the workshop, “――Very likely there’s other workshops besides this one here? Moreover, workshops burning a lot more wood than this place.”
Dvalin was startled.
Certainly, it’s as Eladia said. There existed workshops for the production of glass besides this one.
In an era, where they couldn’t technically attain a high temperature to create glass by directly melting the raw materials like in the modern era, the glass production process had to pass through three stages.
The first work stage is to make the raw materials, silica sand and alkali, fuse at a high temperature, and then rapidly cool the combination down to create pulverized glass grains ― frits. Next, the second work stage consists of creating primitive glass by melting karets ― those frits and scrapped glass. And the third work stage is to make the finished colored and molded product after melting this primitive glass.
Dvalin’s dwarves had constructed another workshop at the foot of the northern mountains where one could find plenty of trees for the first and second work stage, since those require the highest temperatures and needed a huge amount of wood as fuel. And, the workshop right here is a place for only carrying out the third work stage. The primitive glass created at the other workshop is transported to this workshop by using a river. And here they produce the glass utensils.
Souma was surprised after hearing about something like that.
“You use so much wood to create glass…”
In the modern era gas and oil is used to create the high temperatures for melting glass. But, it’s said 20 to 50 times the wood was needed to create glass during the ancient times and middle ages, which lacked those fuels. There’s even the theory that the rapid decrease of the primeval forests in medieval Europe stems back to the development of glass.
However, in this world that still has a lot of untouched primeval forests, the ones feeling a sense of impending danger towards the lumbering of the forests were likely only the elves living in them. Also, the elves had a strong repugnance towards the dwarves entering the forests, their homes, whereas the perception that the forest will disappear was seldom.
But, Souma, who had lived in modern Japan with its protests against such things as environmental destruction through the lumbering of tropical forests, considered that to be a big problem.
However, while that might be true, it’s not like he can suddenly put a stop to all lumbering. He knew after having experienced it first hand after coming to this world, but wood is crucial for the people’s lives as fuel. If the city is going to rapidly grow in the future, its demand for fuel will likely skyrocket. No matter how much it might be for the sake of nature conservation, he will lose everything if he suddenly limits the use of wood and thus disables the life circumstances of the city where he’s currently staying at.
Accordingly Souma offered a compromise to Eladia.
“Mrs. Eladia, can’t you plant new trees?”
Speaking of forest protection, it’s tree-planting that came to Souma’s mind first.
“Tree-planting…you say. What might that be?”
Eladia tilts her head to the side in confusion due to the word she had never heard before.
“It’s about planting saplings ― tree children so that the forest wouldn’t vanish completely after the trees were felled in the world where I had been before.”
Eladia and Dvalin, who are supposed to be elf and dwarf that oppose each other, unintentionally ended up looking at each other.
Something like tree-planting is a concept that hasn’t been even considered in this world.
Contrary to agricultural produce such as wheat, it takes twenty to thirty years for tree saplings to grow up and become usable as fuel. It’s very likely that the people of this world, who still have a life expectancy of around fifty years and below, will reach the end of their life span before that. For that reason the concept of growing trees hadn’t been brought up.
Also, even for the long-lived elves trees and shrubs are part of nature. Something like planting and growing trees with their own hands went beyond their imagination.
Souma exhibits his smattering of knowledge from modern Japan to the bewildered Eladia.
“I have heard that the trees become thin and other plants stop growing if a forest becomes too overcrowded with trees. If you fell trees so that it doesn’t turn out like that, the trees will grow splendidly and develop thick trunks. Same applies for other plants, too. Besides, it will be possible to use the felled trees as lumber.”
That was something Eladia had heard for the first time.
However, Eladia could understand the things Souma was saying, albeit vaguely. Only big trees grow in old forests, and only few plants spread at their roots. However, occasionally, if a tree falls due to a lightning strike or strong winds, a great variety of plants densely grows as if to fill the gap. That’s knowledge she was taught by her father in her childhood. Hence Eladia understands it as causing the same effect with their own hands.
“I don’t think it’s impossible, but…”
However, understanding the theory and actually implementing it are two different pairs of shoes. Eladia feels resistant about remodeling the forest for their own goals.
“I know that it’s difficult, but can’t you do anything about it? Not only for the sake of glass, but even for the livelihood of the city’s people lumber is something indispensable.”
Being asked by Souma in such a way, Eladia can’t flatly refuse either.
Furthermore, Souma makes a request to Dvalin as well.
“I wonder, can’t you use coal (burning stones) instead of wood?”
In modern Japan fossil fuel such as oil and gas is put to use instead of lumber. At present they haven’t found anything resembling oil, but since coal seems to exist in this world as well, he proposed to try using that.
However, Dvalin hesitates.
“Well, that is… I don’t really want to use coal since it releases a rotten, smelly smoke through glass and metal.”
The smell comes from the produced sulfur oxide by burning the sulfur contained within coal. This sulfur oxide also has an effect of corroding the glass and metal that’s being smelted, and it has been shunned in the production of glass and iron products.
“Can you please somehow do something about it?”
Souma put his hands together and asked Dvalin as if begging him. Dvalin didn’t know the meaning behind that gesture, but he comprehends that Souma was entreating him. Even Dvalin can’t easily say no if he’s entreated by Souma, who not only freed him from slavery but also taught him various pieces of knowledge and technologies.
“I got it. I really got it! ――Jeez, I can’t win against you, Sir Soma.”
Only at this time Eladia shared the same opinion with Dvalin who was complaining in an exaggerated manner.
Souma making the main fuel shift from lumber to coal at this time would later on expand towards baking coal in order to remove the tar and sulfur, connecting to the development of coke, but that’s another story.
Souma, who felt relieved after having obtained Eladia’s and Dvalin’s acknowledgment for the time being, looked around the glass workshop’s interior once again.
“However, for the glass of this world to be produced like this.”
Souma, who happened to inspect a glass workshop during a family trip, expressed his astonishment due to the workshop being completely different to the one optimized by modern science he had seen back then.
“What, you have learned how to make glass, Sir Soma?”
Disappointment was contained within Dvalin’s voice. The production of glass was a prided, secret technique for the dwarves. Because Dvalin, who had only been surprised by the various tools and technologies he was taught by Souma until now, had planned to knock Souma out of his wits with this glass manufacture, he felt dejected over having his expectations crushed.
Due to that Souma waved his hands in panic and denied.
“Although you might say that I know of it, It’s just at the level of having visited a glass workshop. Besides, the method of producing glass there was considerably different…”
“The production method was different, you say?”
Dvalin, whose ears perked up upon hearing Souma’s works, asks while furrowing his eyebrows.
“Yes. If it’s the method I know, it’s produced by――” Souma forms an opening by connecting both fists as if grasping something like a cylinder, “――blowing one’s breath like this with a pheeew.”
Dwalin looked puzzled with his wrinkled face.
“Blowing your breath, is it?”
“Yes. You coil the previously melted glass around the end of a metal pipe, and blow into it.”
Dvalin folded his arms with a complicated look.
He never heard about creating a glass container by blowing one’s breath. However, although he had been asked by Souma to make various tools so far, he could easily imagine that all of them were the results of high-leveled technology that’s far beyond the power of dwarves. For that reason even Soma’s talk about blowing one’s breath to make glass is nothing I can laugh off and ignore, Dvalin believes.
“Hey! Is there anything like a convenient metal pipe at hand?”
Once Dvalin called out to the craftsmen working in the workshop, one of them brought a metallic rod. It’s an iron rod used to pick up the melted glass. He made sure that it was easy to rotate in one’s hand by lightly checking its weight. The rod has been hollowed out for the sake of not snatching the heat from the melted glass. It had just the right length once both ends were cut off.
With all eyes of the immensely curious dwarves, who wondered just what was going to start, pinned on him, Dvalin coiled some melted glass around the rod’s end, and blew into it.
In response the orange-colored glass expanded like a balloon. The surrounding dwarves raised their voices in astonishment.
However, their voices changed into disappointed sighs once the swollen glass dangled towards the ground after being pulled by gravity.
“Umm, if I remember correctly, it was done while rotating the rod like this.”
Dwalin grumbled at Souma, who gave that suggestion in a hurry after remembering how the worker in Japan’s glass workshop had been doing it.
“Sir Soma, tell me such things earlier.”
The second attempt. Next he blew into the rod several times while rotating it. As a result he made it expand without it hanging down this time. Furthermore, they thoroughly argued how to detach the glass from the rod, but they discovered that they could detach it by lightly cutting into the glass after it cooled down.
And the finished product was something unshapely like a gourd or an eggplant. But, it was a glass container without a doubt.
Dvalin immediately gathered the workshop chiefs in charge of each work step.
“What do you think about what you’ve seen just now? Tell me honestly.”
Urged to make a statement by Dvalin, it was first the oldest dwarf who spoke up.
“Shouldn’t you as the one who actually tried it tell us about your experience first?”
Since his point was quite reasonable, Dvalin pondered for a short while, and then expressed his own view while scrutinizing it.
“Very likely…no, we can definitely make glass containers with the method just now.”
The workshop chiefs raised voices full of admiration upon his reply.
“But, a method like that is heresy!”
The one who made such an objection was the chief in charge of making the clay molds which are enveloped by the glass.
“I’m fully aware that it’s a heresy. But, I believe this method has tremendous potential. ――Just try to think about it. How much time did it take to create a single container until now?”
All chiefs groaned uniformly at those words.
First they create the core of the container with clay at the tip of a metallic rod. After drying that, they directly soak it in melted glass or twine the glass around it with a string, then they heat it once again, making the glass join together. After hardening it by cooling it slowly, they scrape out the clay core to finally complete one container.
However, the method suggested by Souma only requires attaching the melted glass to the rod and blowing into it.
“I dare say that it will raise the work efficiency by ten ― no, several hundred times. And not only that. Take a good look at this.”
Dvalin shows them the glass he had created before.
“What do you think of this thinness? Could you create something this thin with the method used so far?”
As Dvalin says, in contrast to the glass they had produced so far which allowed you to somehow see a light on the other side if you tried looking at one through it, the glass vessel created through blowing is so thin that you can look at the other side through it just like that.
“In comparison to until now, it takes little time and effort. And, this thinness. ――I think this is an incredible technique.”
What the dwarves had used so far is called core technique. It’s a glass manufacturing method that had been used in Ancient Egypt.
In contrast to that, if you were to speak of glasswork in modern Japan, many people would likely think of the technique of making melted glass at the tip of an iron pipe expand by blowing into it. That technique is the “Glass Blowing Technique” said to have been invented during the era of the Roman Empire.
Not only is this technique still used for glasswork in the modern era even after several thousand years passed, but it’s a basic technique of manufacturing glass vessels, although cutting edge workshops switched the process from human labor to machine-based production methods. The “Glass Blowing Technique,” which is considered as very normal by modern Japanese, was a ground-breaking technique referred to as a huge, technological innovation in glassmaking.
Even the artisans besides Dvalin intuitively comprehended that this is an outrageous technique.
“I won’t tell you to abandon the old technique right away. But I think that we should diligently study and research this technique. What do you think?”
This time there was no objection towards Dvalin’s proposal.
Behind the dwarves, who look at each other with complicated expressions, Souma wondered whether he would return to the city any time soon. He was able to get a general gist of the glass workshop he wanted to see, and if he didn’t return to the city any time soon, the government work he must do would pile up.
“Since I have work to do, I will go back now.”
Dvalin firmly grabbed the shoulder of Souma who tried to return to the city with those words.
“Now, now, Sir Soma. There’s no need to hurry. Won’t you carefully explain things to us for a little bit longer?”
Souma, who suddenly had his shoulder clasped, freezes while opening his mouth for an “Eh?” In addition another dwarf seizes his right hand.
“Right, right! Let us listen to your stories without rush, especially in regards to glass.”
“There’s nothing else you might know?” His left hand is seized.
“Even the most trivial matter is fine. Is there anything else you know?” The cuff of his clothes is grabbed.
“Anyway, spit it out at once ― no, please teach us,” a string is tied around his waist.
And then Souma was dragged deeper inside the workshop.
Shyemul watched that in a daze for a short while, but suddenly came to her senses.
“You bastards, don’t take Soma awaaaay!!”
“…What are those guys doing?”
Garam had something he wanted to consult Souma about in regards to the war preparations, but no matter how long he waited, Souma wouldn’t come back to the feudal lord’s residence. Due to that he finally got tired of waiting and expressly made his way to the glass workshop, but what he found there caused Garam to feel stunned.
“You assholes, give Soma back to me!”
“Yes! Return Lord Soma!”
“Shut up! Sir Soma is going to have a long chat with us!”
Those were the dwarves, who crowded around Souma in the workshop, and Shyemul as well as Eladia who flared up at them with awfully menacing looks.
Once the eyes of Souma, who was surrounded by dwarves, met with Garam’s, he smiled bitterly and waved his hand at him.
Being greatly perplexed by this incomprehensible situation, Garam sent a questioning look towards Zurgu who accompanied him. In response Zurgu scratched his cheek with a finger while likewise baffled, and said,
“To me it looks like nothing but brats fighting over a toy…”
Garam couldn’t do anything but sigh at this overly precise assessment.
However, at that time no one noticed the single old man who secretly slipped into the workshop on the other side of this quarrel.
“Look, look. So this is the famous, rumored drug to make glass, huh? Truly interesting…”
Solon smiled complacently while holding the trona stone powder in his hand.