it was.”
Matthews smiled indulgently. “I’m surprised you don’t recognize them, Doctor. It’s a battery of Leyden jars. They’re for storing an electrical charge. One can either fill them with water or line them with metal foil. The rods you see are made of brass. The more jars there are in the battery, the greater the charge. An electrical discharge can only be performed once, however, after which the storage process must begin again and a new charge built up. Crude, but remarkably effective,” he added breathlessly.
“How is the charge created in the first place?” Hawkwood asked, remembering the theatre audience tumbling like ninepins.
“Friction machines. The charge is collected by rubbing together different materials, such as glass globes and leather.” Matthews held up a finger. “Wait, I do believe I have an illustration.” He left the table and looked along his bookshelves. “Now then,” he muttered to himself. “Adams, Adams, Ad— ah, yes.” He took a book down, opened the cover, wet his finger and began to flick through the pages. His finger stopped moving. “Yes, here we are.” He held the page open for them to see.
“There, a child is being attended by a doctor, possibly for pain or paralysis of the forearm. The friction machine is on the table next to them.”
It was a peculiar-looking contraption, composed of a winding handle, a pulley, and several cylindrical objects with curious, curved attachments.
“You see, the cylinder generator is to the right. That would be made of glass. The main receptor, or terminal as it is sometimes called, is that object in the centre. You see the Leyden jar hanging from the rod at the end of the metal globe? A metal loop goes from the jar to a treatment fork – which, as you see, is touching the child’s forearm. When the handle is turned, the glass generator revolves, building up the charge, which is transferred to the receptor where it is stored. When a sufficient amount of charge is accumulated, the doctor discharges the electricity down the wire to the treatment fork. The result would be a sudden jolt, a stimulation of the senses, activating the nerves and muscles in the child’s arm. It can be most beneficial, I’m told. You know, Cavendish used a battery of Leyden jars to replicate the properties of the torpedo fish.”
Hawkwood realized the shock must have shown on his face, because both Matthews and Locke were throwing him odd looks.
“You’ve heard of the torpedo fish, Mr Hawkwood?” Matthews asked hesitantly.
Hawkwood found he was massaging his left shoulder. Self-consciously, he lowered his hand. “Oh, yes, I know all about bloody torpedoes.”
Matthews’ eyebrows lifted. “Do you now? How interesting. Most people don’t, you know. Poor Cavendish. They accused him of sacrilege for suggesting that a man-made machine could perform in the same way as a creature created by God. The fellow was right about the principle, though.”
Despite the illustration in the book and Matthews’ enthusiastic commentary, Hawkwood wasn’t sure he understood the principle any more than he had before. He wondered if Matthews’ explanation of the last drawing would be any easier to keep up with.
“Another of your illustrations, I believe, James,” Locke said affably, revealing the last sheet.
“So it is!” Matthews exclaimed excitedly. “Ah, now, this is the most sophisticated device of them all. You recall I mentioned Volta when we were looking at the first illustration of Galvani’s frog experiments? It was Volta who concluded there was no such thing as animal electricity, that it was, in fact, the interaction between the two dissimilar metals of the scalpel and tabletop and the salt water in the frog that created the electrical charge. He proved it by constructing what he called his pile. We call it a battery now, as it performs the same function as the friction machines and the jars. The difference with this, however, is that one does not have to store up the electricity in order to discharge it. With this, the electricity remains constant, like the current flowing in a river. There’s no need for winding handles or glass cylinders or jars. It’s all down to a chemical reaction.”
The apothecary tapped the paper. “Using zinc and silver?”
“Yes, well done! Though zinc and copper work equally well. The smaller discs separating the pairs are the equivalent of the frog. Card paper dipped in brine. If you then run one wire from the top disc and one from the bottom disc and close the circuit, the electrical current begins to flow. It’s so simple!”
“And the more discs there are, the greater the charge?” Hawkwood said.
“That’s it!” Matthews frowned and indicated the illustrations. “But how did you come by these?”
“They were left by Colonel Hyde.” Locke dropped his voice. “You know Colonel Hyde is no longer with us, James? Well, Mr Hawkwood and I were putting his things in order and we came across these among his belongings and thought you might like to have them back.”
“Why, Doctor, that’s most thoughtful of you. Thank you.”
“So, did you know Colonel Hyde well, Mr Matthews?” Hawkwood asked.
“Oh, yes. We became good friends. He promised that in exchange for my drawings he would do all he could to pursue my case with the Home Secretary. I expect to hear from him any day now.”
“I’m sure you will,” Hawkwood said. He saw Locke was looking at him. “So the colonel asked you to draw these for him, did he? And did he say why he was interested in the machines?”
“Colonel Hyde believed electricity had the power to change the world. He said one day it would be able to move mountains.”
“Did he now? And how did he think it was going to do that?”
Matthews screwed up his face and had a think, but then shook his head. “He didn’t say.”
Hawkwood stared down at the drawings. So far, everything Hyde had done, he’d done for a reason. So why had he asked Matthews to draw him these? And then Matthews said, “Do you have the other one?”
“Other one?” Locke asked blankly.
“There were three.”
“You gave the colonel three drawings?”
“Yes. Where’s the last one I did for him? He said it was the most important one of all.”
“What was it?”
“He wanted me to design a larger battery.”
“More jars?” Hawkwood said.
“Oh, no, it was the Volta battery he was referring to. He asked me if it was possible to design a more powerful device, using the same principles. I told him it was and showed him how it was done.”
“Did he say why he wanted it?”
“Yes, though I did not understand his meaning.”
Hawkwood waited.
Matthews glanced over to Locke, as if seeking permission for what he was about to say.
“What did he tell you, James?” the apothecary asked.
“He said it would bring him closer to God.”
“All right, Doctor. Suppose you tell me what’s going on here. What do you know that I don’t?”
They were back in Locke’s office. The apothecary was looking pensive.
“How much do you know about the colonel’s background, his education, his medical studies, for example?”
“I spoke with Eden Carslow. They were students together, went to the same lectures. They’d remained friends. That’s why he signed the bond. When he left London, Hyde went to study anatomy in Italy. His studies complete, he joined the army, working in field hospitals in the West Indies, South America, Ireland and Spain. That’s where it started.”
“It?” Locke frowned. “You mean his melancholy?”
“He might have been melancholic by the time he got here, but that wasn’t why they shipped him home, whatever it may say on your admission sheet.”
The apothecary paused in mid stride. “I don’t follow.”
“Colonel Hyde wasn’t returned to England because he was melancholic. It was because he was murdering French prisoners of war and using them for butchery practice. He was placed here because he was a friend of Carslow’s, and Carslow has influence with the governors.”
“What do you mean by ‘butchery practice’?”
“He was trying to rebuild them.”
“Rebuild?”
