121. Near Castle Inter Lucus
“We heat sand and beech ash together in this furnace. Master Gausman called this first step ‘fritting.’ Ernulf and I have been making frit for three weeks now, saving up a good supply. The frit furnace isn’t hot enough to melt sand, but settles the ash and sand together. Two days ago we moved to the second stage, with the main furnace.”
Stacked firewood lined the north wall of Isen’s A-frame glassmaking factory. Students of Collegium Inter Lucus stood with their backs to the wood, watching and listening to Isen’s lecture. Besides the frit furnace and the much taller main furnace, there were workbenches and mysterious looking tools hanging from hooks. The glassworks was very warm, even on a late winter morning. Marty wondered what it would be like come summer.
A group visit to the glassworks was Marty’s idea, inspired by grade school field trips in his childhood. The excursion served as a break from daily lessons for the children, and it honored Isen’s successful launch of glassmaking between the lakes. Marty had already asked Ora to plan a “Grand Opening” for the glassworks, to which villagers in Senerham and Inter Lucus would be invited.
“To actually make glass, we put some frit in a crucible—that’s a special bowl that won’t crack even when it’s very hot—and it goes into the main furnace. We put in a crucible this morning, before you all had breakfast, and either Ernulf or I have been feeding the fire and watching the furnace all day. The frit in the crucible has melted into glass, so now we’re ready to blow.”
Isen put on a pair of thick cloth gloves and held up a clay tube about three feet long. “My blowpipe. The other end has to be hot to gather glass.” Ernulf, also wearing gloves, opened a small door on the furnace, and Isen inserted the blowpipe. Sweat sheened on Isen’s face as he rotated the tube for several minutes. “And now we pick up a gather.” Isen squatted to face the opening of the furnace and moved the tip of the tool into the white-hot liquid in the crucible. Most of the children couldn’t see into the furnace, but those immediately behind Isen watched the tip of the blowpipe intently.
Isen slowly backed away from the furnace with a round bulb of glass hanging from the tip of the blowpipe. Marty heard a collective intake of breath from the onlookers. “Oh! Look at that! Wow!”
Isen swung his instrument in a small circle while puffing little breaths into it. Ernulf shut the door to the furnace, reducing the tremendous heat coming out, and picked up two flat wood paddles. The apprentice stood ready to respond to any gesture from Isen while the molten gather on the end of Isen’s tool became a round ball. Isen lowered the glass ball onto the concave surface of a wooden block, puffing and turning the glass. Marty was struck by the image of a jazz musician improvising. Occasionally Ernulf used the paddles to help shape the glass.
Isen flicked an elbow toward the furnace without lessening his attention on the glass ball, which was now about six inches wide. Ernulf quickly set aside the paddles and opened the furnace door; Isen reinserted the glass ball. He continued turning the glass while speaking. “I’m reheating the glass a bit so I can work it. Some furnaces have a special door for this part; they call it the ‘glory hole.’ But we built our furnace simple and use just the one door. Course, I have to be careful not to touch anything inside.”
Isen brought out the glass ball, and Ernulf closed the furnace. Once again Isen worked the glass on the wooden block, but now he drew the top higher, and Ernulf’s paddles pushed the slowly rotating piece into a cylinder shape. At a signal from Isen, Ernulf picked up a tool that reminded Marty of a giant set of tweezers; with the iron tips Ernulf began cutting the cooling glass a few inches from the blowpipe. But the workmen did not cut the piece completely free; first, Isen moved it to a wood bench and let the weight push down to create a flat bottom. They placed the vase—for that’s what the piece looked like—on two metal rods. Isen finished cutting free the blowpipe and the bit of glass affixed to it and handed it to Ernulf, who scraped off the excess glass into box that contained other such bits. Glass was too valuable to be thrown away; later the scraps would be melted and made into new pieces.
The top edge of Isen’s vase was still pliable; he shaped it with smaller wood tools to smooth out irregularities. Then Ernulf climbed onto a stool to open a door high on the furnace. Isen picked up the vase they had made on its punty rods and they slid it in.
“If glass cools too quickly,” Isen explained, “It’ll break. So we put it in the ‘annealing oven.’ It’s above the main furnace and not as hot. We’ll let the new piece cool slowly. In a day or two we’ll take it out. If it cracks or if I don’t like the color, we’ll toss it in with the cullet.” Isen indicated the box of glass scraps. “Later, we’ll smash the cullet down into bits so it’ll melt easier, and make something useful.”
Isen took off his gloves. “Glass making takes lots of firewood ’n lots of practice. Ernulf here has been learning real fast, ’cause he grew up ’round his dad’s smithy.”
The students asked questions.
“Could you put a handle on the vase shape and make a pitcher?”
“How do you make glass of different colors?”
“The ‘gather’ came out round like a ball—how do you make it flat and square for windows?”
“Will you make things for Inter Lucus?”
“People from Senerham will buy glass too, won’t they?”
“How many glassmakers are there in Down’s End?”
Lots of questions, questions that validated Marty’s choice of students. They have genuine curiosity; they want to learn how things work. They see that a glassworks will bring change and they’re thinking of the big picture. Manufacturing glass here at Inter Lucus might lead to competition with Down’s End. It might lead to trade with other places.
“Can you make a glass string?”
Alf’s voice, piping from the end of the line of students, interrupted Marty’s reverie. Isen hesitated before answering. “Yes. Glass can be shaped without blowing it.”
Isen picked up an iron rod like the ones they had used under the vase. “If I pick up a gather with a punty rod like this one, I can’t blow into it. But I can draw it out into a string of glass, and I can fold it and mold it. Then, once it cools, the string will have whatever shape I gave it. With practice I could make a brooch, for example. The kind of thing rich aldermen in Down’s End give to their wives.” There was a kind of longing in Isen’s voice; he had told Marty once of his dream of making a glass swan and other beautiful things.
Alf asked, “Could the string be straight? And very, very thin? It wouldn’t have to be long.”
Isen was puzzled. “Making a straight bit of glass would be easy, especially if it is not long. But why would anyone want such a thing?”
Tayte Graham said, “A glass hairpin would be pretty, but it would break. A glass needle could be really sharp, but again, it would break.”
Alf ignored Tayte’s suggestions. He was looking up at the A-frame walls as if she weren’t there. “Very thin. Very straight. And they have to be…smoked.”
At first, Alf’s strange choice of words elicited derision. Someone said, “You smoke meat, not glass, silly!”
But then Ora said, “You’ve been dreaming again, haven’t you, Alf?”
The boy sighed deeply, and he looked at Marty. “Aye. I dreamed it. For the CPU.”
Here ends part three of Castles.
Copyright © 2014 by Philip D. Smith.
All rights reserved. International copyright secured.