“Yes.” Carrick brushed back an unruly lock of hair from his brow. “And I think that Wayland may have actually provided us with a clue pointing to Jasper’s ultimate discovery. I recognized certain elements . . .”
His voice betrayed a note of rising excitement. “It’s an area of mathematics called the ‘calculus of variations,’ first developed in the last century by the great Swiss mathematician Leonhard Euler and the Italian-born Frenchman Joseph-Louis Lagrange.”
“The calculus of variations?” murmured Alison. She made a face. “You might as well be speaking Greek or Hindi.”
“I know, I know,” said Carrick. “But trust me, it offers a wealth of exciting new possibilities for understanding how our physical world works!”
“We’re just beginning to understand how mathematics can be used to create models of natural processes and then applied to science, engineering, mechanics, and the like,” explained Cordelia. “These applications include practical problems such as how to design longer, stronger, and safer bridges. For example, the calculus of variations can be used to analyze the distribution of weight loads throughout a bridge and to establish the center of its mass. It can also show how a bridge should be expected to respond to vibrations from wind, traffic, and the stress imposed by its own cables and towers.”
“In formulating the calculus of variations, Euler and Lagrange further developed the work of Sir Isaac Newton and the German polymath Gottfried Leibniz, who had invented calculus a century earlier,” interjected Carrick. “At the heart of the calculus of variations is something called the Euler–Lagrange equation. A current mathematician—a woman by the name of Marie-Sophie Germain—has used some of these techniques of the calculus of variations to develop more advanced mathematical models for the issue of vibrations and how they affect structures like bridges—”
“Oliver, let us not overwhelm our friends with such advanced mathematical concepts.” Cordelia made a face. “Indeed, I confess that I don’t entirely understand the calculus of variations and its ramifications. We need to do more study on it.”
“Cordelia is going to borrow some rare mathematical books from a friend of hers at the Royal Institution and bring them back here,” said her cousin. “Then we will set to work with Mrs. Guppy and Mademoiselle Benoit to see if we can figure out if I am right in assuming Milton’s innovation centers around the calculus of variations.”
“Let us hope that is so,” murmured Charlotte.
“I am going back to the earl’s workroom and will get started,” said Carrick, waving off McClellan’s offer of breakfast.
Cordelia waited for her cousin to leave the room before turning to a different topic. “While we work on the mathematics, Kit is going to concentrate on discovering the identity of Axe. He has some meetings today with several of the supervisors overseeing the Bristol Road Project, as they are in Town for the transportation conference,” she said. “He’s also going to make some inquiries regarding the most talented bridge engineers in the area and see if any of them has a connection to Jasper Milton.”
“And I will take a careful look throughDebrett’s Peeragefor any clue to the identity of Axe,” said the dowager. “A mother’s maiden name, an image on a coat of arms—there’s a wealth of important information within its pages if one knows what to look for.”
“I’ve already done that, having learned from you during previous investigations how much that book can reveal,” replied Charlotte. “Alas, no luck.”
Raven put down his fork. “What can I do to help?” he said to Cordelia.
“Alas, sweeting, Cordelia may be able to swear her cousin to secrecy, but Mrs. Guppy and Mademoiselle Benoit have seen you as a ragged urchin,” said Charlotte. “Were they to learn that you are our ward, it might raise awkward questions—”
“And put our family secrets in danger,” finished Raven. Disappointment rippled in his eyes, but he nodded in understanding. “Oiy, I’ll be careful to keep out of sight.”
“We all will,” piped up Hawk.
“Actually, there is something you can do without putting the family at risk,” offered Cordelia. “You can gather all the mathematical books in Wrex’s library, especially the ones on Leonhard Euler’s work, and stack them on one of the worktables for me to fetch when I return from the Royal Institution.”
Charlotte gave her friend a grateful smile. “And I had better go and compose my next satirical drawing for Mr. Fores.” The previous night’s discussion with von Münch had sparked an idea, though it might be a dangerous one. She needed to think it over.
The quiet solitude of her workroom was a welcome respite from the turmoil of the last few days. Charlotte went through the comforting ritual of sharpening her pencils and pens, uncapping her inkwell and selecting a fresh sheet of paper to begin her preliminary sketching.
As always, she closed her eyes for an instant and finished her preparations with a whispered thanks to Hephaestus, the god of art and creativity for both the ancient Greeks and Romans. It was a habit she had formed while living in Rome, a city in which even the smallest sun-bleached stone seemed to thrum with a silent ode to the imagination.
“Perhaps I’m mad,” whispered Charlotte. But the moment her pencil point touched the paper and began to move in concert with her thoughts, she felt all her uncertainties unknot and float away.
A. J. Quill was fearless.
Caught up in the rhythm of mind and body at work, she lost track of time. One sketch finished, she moved on to a second idea and then sat back to scrutinize the results.
As her gaze shifted to the first one, Charlotte gave an involuntary gasp. It wasn’t often that she could take herself by surprise. The image was powerful—perhaps too powerful.
“A. J. Quill is bold, but not reckless,” she told herself. And this particular drawing would stir up a maelstrom within the highest circles of government.
It depicted a massive arched bridge, one thin end planted on the tiny island of Elba and the other widening as it curved and came to rest in the heart of France. Straddling the top of the curve, as if he was riding his war horse, was Napoleon Bonaparte in full battle dress. Charlotte could already envision the title—A Bridge to the Future?
She stared at it for a moment longer, then pushed it aside. The second sketch was safer, though it still raised important questions that would no doubt capture the public’s attention.
They trust me to tell them about issues that affect their lives.
The drawing was based on the same bridge theme. But this one showed an arched bridge with one end anchored in London and other coming to rest in the industrial city of Manchester. Rather than a single famous figure, it showed a crowd of working-class men and women trudging across its span.
