by Eric Flint
The gelatin plates she had taken to China came in three speeds, slow, moderate and fast, and were marked accordingly. At the Brennerei und Chemiefabrik Schwarza factory, she had been told how these were made, in case she had to make them on her own. The silver halide was made by reacting silver nitrate—what a seventeenth-century alchemist would call “lunar caustic”—with a halide salt, usually a bromide. The sensitivity of the plate depended on which halide salt you used, how fast you added the silver nitrate, the “ripening” temperature at which you grew the silver halide grains, and the length of the ripening period. You could also add chemical sensitizers, such as ammonia. To complicate matters further, each batch of gelatin was a bit different.
For outdoor shooting of static subjects in bright sun, she preferred to use the slow plate, and fine-tune the image during the development process.
Judith pulled out the plate holder and put it in a protective bag, which in turn went into Wei’s little cart.
“Okay, let’s get a close-up,” Judith told Wei. The two of them grabbed the camera, still attached to the tripod, and laid them carefully on the bed of the cart. Wei grabbed the arms of the cart and they started toward the pagoda in the distance.
Chapter 25
Zheng Zhilong’s local office
Fuzhou
Judith Leyster was walking toward the darkroom that Zheng Zhilong had permitted her to set up in his family’s office in Fuzhou when she was accosted by his young son, Big Tree. “Aunt Judith, what are you doing? May I help? Or at least watch?” he asked. In China, it was not unusual for “Aunt” to be used as a term of respect for a female member of one’s parents’ generation.
“I am developing photographs. You may watch and help if your father gives permission,” she said. “And if you follow my instructions exactly, because we must work in near darkness.”
Big Tree was quivering with eagerness. “I will find him; I will be right back; don’t start without me.” He ran off.
“I will begin the preparations,” she called after him. But he was long gone.
* * *
Big Tree ran into his father’s study and braked to a halt. He caught his breath, bowed politely, and said, “Excuse me, Esteemed Father.”
Admiral Zheng Zhilong set down the communiqué he had been reading. The multitudinous paperwork of his positions, official and mercantile, had followed him to the Zheng’s office in Fuzhou. “Yes, son?”
“Judith Leyster invited me to watch the process by which she makes photographs. What are photographs, Father?”
Zhilong gave silent thanks to Jim Saluzzo for explaining photographic technology in such way that Zhilong could understand. It would not do for an admiral to be unable to answer his son’s question.
“They are ‘seized shadows,’ my son. You have seen my spyglass?” Big Tree nodded. “It uses specially shaped pieces of glass to bend light. Our visitors call them ‘lenses.’ The lenses direct the light onto flat pieces of glass that have been coated with a solution that darkens in response to the light.”
“Magic!” exclaimed Big Tree.
“Not magic. You have seen the secret messages I have gotten sometimes, where the message is revealed by heat. Just as there are substances sensitive to heat, there are ones sensitive to light.”
“Ah.” Big Tree pondered this. “Does the solution stay dark when the light is taken away?”
Zhilong was a bit fuzzy about that detail. “You know that before I was an admiral, I was the captain of a ship?”
“Yes, Father.”
“A captain can’t do everything. Some things must be done by his officers, or his crew. So I am delegating to Judith Leyster the responsibility for explaining everything you want to know about photography.”
Zhilong had immediate second thoughts about how this statement might be interpreted. “Excuse me, you are to treat her as your tutor. Spend more time watching and listening than you do talking. Choose your questions wisely; let her get her work done. Now, report to Teacher Judith for duty!”
Big Tree saluted and ran off.
* * *
While Judith waited for Big Tree to return, she took down chemicals and prepared the various baths for developing and fixing the negative image on the glass plate. As she did so, she thought about her childhood.
Big Tree was, she understood, eleven years old. When she was eleven, her father was still a successful brewer, and she lived in a comfortable middle-class household and took art classes merely for enjoyment. It was not until 1625, when she was sixteen, that her father went bankrupt and she had to paint for a living. Despite her talent, it had been a struggle to win the right to paint professionally.
Having earned master standing in Haarlem, she had expected to run a studio. And from her biography in Grantville’s encyclopedia she knew that were it not for the Ring of Fire, she would have married Jan Miense Molenaer in 1636, and gradually retired from painting as she devoted more and more of her time to her children.
Instead, she was now in China, and still single.
Big Tree’s shout broke into these reflections. “My father says it’s okay!”
“Come in, then,” said Judith. She opened the door to the darkroom and grabbed a sign from just inside. “Hang this on the outside.” The sign read, Do not disturb!
Big Tree did so. He studied the sign and said, “This isn’t scary enough. You should add, ‘If you do, the demons of photography will devour your insides!’”
She laughed, motioned him in, and closed the door. The only light in the room came from a bull’s-eye lantern that Judith had lit while Big Tree was busy. And that lantern gave off less light than one might expect, because there was a dark red filter glass, made in Grantville, covering the opening.
Big Tree studied the room, whose contents were barely visible in the crimson gloom. “There aren’t really demons in here, are there?”
“Absolutely not,” Judith assured him. “Photography is just optics and chemistry, and developing is the chemistry part. I know that Jim Saluzzo has told your father how photographs are made. Did your father tell you?”
“He said that your ‘camera’ has a glass ‘lens’ and that it casts an image on the glass plate. The glass plates are coated with an elixir that darkened when exposed to light. It captures that which was bright as dark, and that which was dark as bright. My tutor would say, like yin changing to yang and yang to yin.”
The “elixir” was silver halide in a gelatin binder. However, SEAC was keeping that as a trade secret. Much as Judith would have liked to have been more specific, the point of the photographic demonstrations was not just to impress the Chinese, but also to persuade them to buy cameras, dry plates, and chemicals from SEAC.
“That’s almost right. The elixir changes its nature when it is exposed to light, but you can’t see the change—the image is latent, hidden—until I add another chemical, the developer. Elixir plus light plus developer equals black. What do you think would happen if I opened the door to the darkroom while the plate was in the developer, if it were light outside?”
“The light would come in and turn it completely black!” Big Tree suggested excitedly.
“Indeed, it would, which is why the darkroom is closed.”
“But then why have a light at all?” he wondered.
“If we had to work in complete darkness, we couldn’t see where anything was, and how well the photograph was developing. So we keep the light dim and red, red being the color of light that the elixir is least responsive to.
“Now, we wait a few minutes, for our eyes to adjust to the lack of light.”
It suddenly struck Judith that an eleven-year-old boy might be nervous standing and doing nothing for that length of time in a strangely lit room. “Why don’t you tell me about your studies while we wait.”
And Big Tree talked to her about them for a few minutes until Judith said, “I think we can begin now.”
She pulled the dry plate out of the light-tight protective bag and
set it in the first bath.
“What’s that?” asked Big Tree.
Judith took the plate out and put it in a second bath. “This is the developer solution, in a white ceramic tray.” Again, she didn’t give specifics, but the developer was an alkaline solution of pyrogallol with a pinch of silver nitrate. When the plate was exposed to light initially, some of the silver bromide in each grain was reduced to silver. The point of the developer was to intensify the image by further reaction of those grains that had already begun to react. The pyrogallol was made by heating gallic acid, which was found in tannin. She preferred it to hydroquinone because she could make more herself, if need be.
“Now, watch the plate. Since this is one of the photographs I took outside, of Xichan Temple, it has sky in it. The sky was the brightest part of the scene so it will be the first thing visible. Remember, it will darken gradually!”
Big Tree stared at it as intently as a cat watching a bird on a branch that was just a little too high to reach.
“Aunt Judith, I see some gray!”
Judith leaned over to check, and then glanced at a sandglass she had set nearby. “So you do, and it is appearing a bit too soon, too quickly. I must compensate.”
“How?”
Judith added a few drops of a chemical from a small dropper bottle to the developer bath. “With this,” she explained. “It slows down the darkening reaction.” The chemical in question was potassium bromide; she also had a similar bottle of calcium carbonate solution to accelerate the reaction if it were going too slowly.
They watched as the image continue to develop. After the sky, the architecture became visible, and finally some of the foliage. “Okay,” said Judith, “it is time to put it in the rinse bath and then in the fixer bath. The fixer makes the image permanent and stable in light.” The fixative was the traditional hyposulfite of soda, which would dissolve the remaining “non-image” silver bromide, without affecting the silver metal. Another trade secret. Ammonia could also be used, but the smell might give away the secret. She followed her own instructions, and then rinsed the fixed plate.
“One down. Ready for the next one?” She handed Big Tree a black bag. “Here, gently take out the plate and put it in the developer tray, just as I did.”
* * *
At last Judith said, “that’s enough for today. Tomorrow, we’ll make contact prints to show your father and the scholars we met at the governor’s banquet.”
* * *
Making contact prints involved clipping together the developed plate with light-sensitive paper, and exposing the emulsion side of the paper to full sunlight through the plate. Where the plate was still clear, the light would pass through, and darken the paper, and where the plate was black, the light would be blocked and the underlying paper remain unchanged. In this way, the glass plate negative was reversed to make a positive print.
Judith Leyster and Big Tree made a dozen or so prints, and then of course they went through them all and compared them to the glass plate negatives. Most of them were outdoor exposures, taken in Fuzhou on Judith’s excursion, but there was one exception.
“And here’s a print of you and your father playing weiqi. I am fortunate that you both sat still, in deep concentration, for a long time, as it meant I was able to make an indoor exposure.”
Big Tree look puzzled, so Judith elaborated. “It is darker indoors, so we must wait for more light to hit the plate. Think of it as being like rain falling into a well. If the rain is light, then you must wait longer for the well to fill.”
“I understand,” said Big Tree. He reached for the print, but Judith pulled it back.
“Wait, I must sign it.” She found her drawing tools and in the lower righthand corner drew a stylized “JL,” with a horizontal bar across the middle of the two letters extended to the right, and an “x” drawn across the bar at its right end, forming an asterisk.
“What’s that?” Big Tree asked.
“My initials, in Dutch, and a star.”
“Why a star?”
“You know a little Dutch, I think?”
Big Tree nodded.
“Because my name ‘Leyster’ means ‘lodestar,’ the star to which a ship’s compass points. What you Chinese call—”
“‘The Great Imperial Ruler of Heaven,’” Big Tree said. “That is a powerful name, Aunt Judith.”
On board the Rode Draak
“Now, look out the porthole through this,” said Jim Saluzzo, handing a cylindrical instrument to Father Aleni. “Put your eye here,” he added, pointing to a small hole in one end.
“Is it some kind of telescope?” asked Aleni. He turned it to look at the other end. “No, couldn’t be. This end is white, not clear. And what is that grinding sound?”
“Just look, and I’ll explain everything,” said Jim with a smile.
Aleni complied. “Mary, Mother of God. That’s beautiful.”
“Turn the far tube,” Jim instructed.
“Oh, my, the image changed. Now, I must insist you explain.”
“It’s simple, really. You are looking down a triangular channel formed by three mirrors that touch at their ends and face the center line. Beyond the channel is the object cell, which holds pieces of colored glass. The mirrors create repeating images of the objects visible through the triangle. When you shake the tube, the glass fragments move around, changing the image. We call it a kaleidoscope; it was invented in the early nineteenth century.”
“What is it used for?”
Jim laughed. “In my day, mostly for entertaining children. We brought them to use as presents for high officials. We also have teleidoscopes; those have clear glass in place of the object cell, so the mirrors fracture the view of the surroundings.”
Aleni reluctantly handed back the kaleidoscope. “The images are, perhaps, a metaphor for life. Each moment is different from the one before; you cannot truly recapture or redo the past, so you must be sure that you have lived every moment in accord with Christian principles.”
There was a knock at the door of Jim’s cabin.
“Come in,” said Jim. “Ah, Doctor Bartsch, I would like you to meet Father Aleni.”
“Bartsch? Jacob Bartsch?” said Aleni. “The mathematician who married Johannes Kepler’s daughter?”
“Well, yes, but hopefully that is not my only claim to fame,” said Bartsch coolly. “Surely you have heard of my treatise on the astronomical use of the stellar planisphere?”
“Of course. It is a most useful manual of practical astronomy. Not yet translated into Chinese, I’m afraid.”
“And what of my ephemerides of 1630? They were the first to be based on my father-in-law’s Rudolphine Tables.”
Aleni pursed his lips. “I am not sure of the details, but I believe that my colleague in Beijing, Father Schall, received a letter from your father-in-law that provided a portion of the Rudolphine Tables, that permitted the calculation of eclipses.”
“And you are using them for calendrical calculations? Even though they are based on his hypothesis that all of the planets, and even the Earth, travel around the Sun in elliptical orbits?”
“Please, Doctor Bartsch. Father Aleni and his colleagues were bound to follow the teachings of the Catholic Church,” said Jim. His remark eased the tension in the room, but only temporarily, as he added, “I am sure those teachings will change now that the books of Grantville reveal that the Keplerian theory is proven fact, not mere hypothesis, and follows from Newton’s law of universal gravitation.”
“Oh, yes, I am sure they’ll issue an apologia,” said Bartsch. His tone suggested otherwise. “But I was come to say that Ambassador Garlow would like me to bring Father Aleni to him in the Great Cabin.”
* * *
Eric Garlow motioned for Father Aleni to sit down in one of the ornately carved chairs at the wooden table in the Great Cabin. From the pronounced curve of the wall against which the table was positioned, it was obviously part of the hull. Garlow waited politely until Aleni
had taken a seat and then sat down himself.
He went straight to the point. “I’ll be blunt, Father Aleni. We’re here to develop trade, not to pick a fight with the Catholic Church. But if the Catholic Church picks a fight with us, it will wish it hadn’t. The only reason you’re tolerated by the Chinese government is because you can construct a more accurate calendar of astronomical events than can the Chinese or the Muslims. But we can do better than you can, and I’ll let Doctor Bartsch explain.”
Bartsch cleared his throat. “We have a more accurate set of current orbital elements for each of the planets, as well as the Moon, than you do, and we know how they will change with time as a result of gravitational perturbation. We know that your latitude and longitude for Beijing are wrong, and that affects eclipse timings. We can show the court officials in our telescopes that there are planets that you never told them about—Uranus and Neptune—that we can add to our version of the calendar.
“We brought with us a detailed printout of predictions for Beijing for the next decade. And if for some reason we need to make similar predictions for another Chinese city, such as Nanjing, we can do so with the software on Jim Saluzzo’s laptop. Or I can grind it out with pencil and paper using the up-time formulae. Which you don’t have.”
Father Aleni spread his hands. “You understand that I do not set policy.”
“Yes,” said Eric, “but you have been in China a long time now.”
“Indeed. And as an old China hand, I know that a good half of the Jesuit priests in China are Portuguese, and will be inclined to protect Macao’s monopoly on direct European trade with China. And the rest of the priests are conscious that the route by which money and new priests come to China lies through Macao, and thus we must be mindful of Macanese interests.”