Part 15 (1/2)
CHAPTER NINETEEN.
The principle of a steam engine was simple. A coal-fired boiler heated water till it produced steam that flowed into a cylinder. Cooling the steam created a partial vacuum so that normal air pressure rammed the piston down into the cylinder. A crossbeam translated that movement into power, usually to operate a water pump. David knew the principles inside and out. It was the details that were tricky, especially when a man was trying to build a better engine.
Burning coal had already raised the water in the boiler to the boiling point, so David nervously checked over the other components of his model. The insulated cylinder and pump looked fine, as did the condenser and piping that connected the components.
Nonetheless, David worried. This was a jury-rigged engine, thrown together as quickly as possible to test his theory that a separate condenser would be far more efficient at cooling steam than Newcomen's method of spraying cold water in the cylinder, which wasted huge amounts of heat. Sarah had calculated that only one percent of the energy was used effectively. Surely David could build an engine that did better than that.
”This engine will work a fair treat, sir,” Peter Nicholson a.s.sured him.
The youth had proved to be an apt a.s.sistant, willing to labor long hours and having deft hands for mechanical work. He was as excited as David, and he wasn't the only one. A dozen other mechanics, craftsmen, and urchins from the neighborhood were crowded into the workshop to see the test. Their fellows.h.i.+p and support made David feel like part of a community for the first time since his childhood.
”Let 'er rip,” Gaffer Lewis said around his pipe. ”If 'er don't work, ye'l just have to build another.”
There was general laughter. All of these men had experienced failures as well as successes. They would celebrate if David's engine worked, and offer sympathy and practical advice if it didn't.
Sarah should be here, too. Without her calculations and patient explanations, David never would have fully grasped the principles of heat, steam, and evaporation. But he had sent her back to the house earlier, before the boiler was stoked up. Though the chance of an accident was slim, neither of them wanted to risk the health of the precious babe she carried.
”Start the engine, Peter,” David ordered.
Peter complied with a dramatic flourish, pulling down the handle that opened the valve and allowed steam to rush into the cylinder. With hisses and clanks, the piston rammed into the cylinder. A cheer broke out from the watchers as the crossbeam began pumping up and down. ”She works, sir!” Peter said jubilantly as the pounding piston found a steady, powerful rhythm.
”That she does!” David watched the hammering crossbeam and exulted in the clamor of his engine. Even without measuring, he knew that his engine would be able to pump water from a flooded mine far more efficiently than the Newcomen engine. And how many other uses might clever men find for such a source of power?
He frowned as a high-pitched hiss joined the sounds of bubbling water and clanging metal. Could there be a leak? He moved toward the engine to turn it off.
Kaboom! The cylinder exploded and chunks of bra.s.s flew about the room.
”b.l.o.o.d.y h.e.l.l!” David dived behind the worktable for protection. Even as metal smashed into walls and furniture and the sharp sound of shattering gla.s.s filled the room, the other men were doing the same. Thank G.o.d Sarah wasn't here!
When the only sound left was the hissing of the boiler as it pumped steam into the room, David cautiously raised himself to a crouch. ”Is everyone all right?”
Voices spoke up attesting to their safety. Peter's head appeared above the other table. ”We were lucky,” he said, his voice unsteady. As the man closest to the engine, he had been at the greatest risk.
”Very lucky.” The dry, cultivated voice came from near the doorway. ”But your engine does indeed work. Congratulations, Mr. White.”
Recognizing the voice with a sinking heart, David scrambled to his feet. ”Lord Falconer? I didn't know you were coming today. I'm sorry for . . . for this.” He waved a hand to indicate his workshop. As near as he could tell, the window facing the house was broken and tools had been knocked to the floor, but the damage didn't look too bad. The model engine was a disaster of fractured metal and twisted pipes, though.
”You mentioned in your last note that you would be testing today, and I didn't want to miss that.” Falconer was dressed plainly, more like an advocate than a lord, but his aristocratic presence was unmistakable. When he crossed the room, the other men withdrew warily. They weren't used to seeing earls in workshops.
Falconer eyed the wreckage critically. ”Where did you get the cylinder? It looks like cast metal rather than a machined piece.”
”You're right, my lord. I borrowed the cylinder from Jeb Hitchen here.” David nodded at a silver-haired man, a metal caster from two streets over. ”I'm sorry, Jeb, I'l replace it.”
Hitchen shrugged. ”There must have been a weakness in the casting or it wouldn't have failed. 'Twas worth it to see your engine working.”
”The pressure was too high for that cylinder.” David forced himself to meet the earl's gaze. ”I was impatient to see if the design worked, so I cobbled this model together. If I'd taken the time to build the lathe and machine a cylinder properly, this wouldn't have happened. At least, I hope it wouldn't,” he added punctiliously.
Falconer gave a surprising grin. ”If I'd spent as long developing this engine as you, I'd be impatient, too. But now that you know the principle is sound, perhaps you should spend more time on the next model. And add a pressure relief valve.”
”Yes, sir!” David said fervently. He touched the chain that connected the crossbeam to the piston. ”But ' twas a pretty sight while it worked, wasn't it?”
”That it was.”
”David, what happened?” Sarah had arrived, drawn by the noise. She stopped in her tracks, her eyes widening as she looked at the ruined engine. ”Oh, dear!”
”No harm was done,” Lord Falconer said. ”And your husband has proved that he can take the steam engine to a whole new level of efficiency.” He glanced at David. ”Though you might want to experiment using lower pressures at first.”
”Aye.” Now that alarm over the explosion had died down, David realized that his design had succeeded. It had worked! Today, in a small way, the world had changed, and he was a step closer to dressing Sarah in silk and lace.
Falconer was studying the engine with interest. ”Mind if I take a closer look? It looks as if you've made some refinements on your original plans.”
”I did, sir. See how cold water circulates in the jacket of the condenser?” As David explained, Falconer and the other men gathered around, asking questions and tossing out opinions. In no time at all, the neighborhood craftsmen had forgotten they had an earl among them. What mattered was that Falconer had the makings of a fair to middling engineer.
When the library door opened, Meg didn't bother looking up from her book. ”You can set the tea tray on the table, Hardwick.”
”Yes, ma'am,” a deep voice said.
Startled, Meg glanced up to see Simon placing the tray on the table. ”I saw Hardwick coming this way with the tea, so I had him double everything.” Simon poured two cups of China tea and handed one to Meg. ”Having spent a vigorous afternoon discussing David White's steam engine, I felt in need of sustenance.”
Meg laughed as she stirred sugar into the delicate porcelain cup. ”I take it you decided to watch the test. Did it go well?”
”Well enough, except that it exploded after two or three minutes.”
Meg halted, the teacup halfway to her mouth. ”Was anyone hurt?”
”No, but there would have been a few injuries if I hadn't been there.” Simon sat in the chair opposite. ”Now I know why intuition was urging me to go see the test. I arrived just as the engine was started. When it exploded, I was able to s.h.i.+eld everyone from injury. There's quite a community of engineers and inventors nearby, so he had a good audience.”
”Is Mr. White's design flawed?”
”No, he just built this model in haste to see how it would work. I suggested that he build his next model to higher standards of quality. He agreed rather fervently.”
”I wonder if today's explosion was the possible death I saw for Mr. White?” Meg said thoughtfully. ”I'd like to think the danger is past now.”
Simon hesitated. ”Perhaps. But my feeling is that there might be other threats in the future.”
Before Meg could ask Simon to elaborate, his secretary, Jack Landon, opened the library door. ”Sorry to disturb you, sir, but you have visitors you'l want to see as soon as possible.”
Landon stepped aside to allow a couple to enter the library. Simon rose and went to meet his guests with a broad grin. ”Duncan, you're in London ahead of schedule!”
The other man laughed as they shook hands. ”You're losing your touch, Simon. You should have known when I would arrive before I left Scotland!”
Meg studied Macrae with interest. He bore little resemblance to his pet.i.te, redheaded sister. Tall and dark and broad, he radiated force. It was easy to imagine him calling a lightning strike if he was displeased. Simon looked lean and elegant by comparison, but there was an interesting sense of balance between the two men.
”Where is my G.o.dson, Gwynne?” Simon asked as he kissed the cheek of the woman obscured behind Macrae's large frame.
”With Jean and Lady Bethany, being spoiled abominably,” she said with a laugh.
Simon turned to Meg. ”Here are Duncan Macrae and Gwynne Owens, of whom you've heard so much. They are more formally known as Lord and Lady Ballister, though it pains Duncan to admit to an English t.i.tle.”