Grant was the first person off the train. The conductor reached to help him, but he waved the man away. He went slowly, holding on to the exit rail with his left hand, his right arm in a black silk sling. Ramsey stepped forward to greet him.
“I hope I did the right thing by asking you to be here, Ulysses. I was assured that you were on the road to recovery.”
“Very much so — and damn bored with all the sitting around. This little trip will do me worlds of good. If you want to know, your telegram was a gift from the gods. But did I detect an air of mystery in your request?”
“You did, General, you certainly did. But it is all a mystery to me as well. This is Garret Davis, Mr. Ericsson’s works manager. He is also very secretive in the matter.”
“I am most sorry, gentlemen,” Davis said with a weak smile. “But I have specific orders. If you would please come this way — there is a carriage waiting.”
It was a short drive from the station to Ericsson’s shipyard. A high wall surrounded the yard itself and there was an armed soldier guarding the gate. He recognized Davis, saluted the officers, then called out for the gate to be opened. They climbed down from the carriage in front of the main building. Davis moderated his pace to accommodate Grant as they entered the building.
Ericsson himself came out to greet them. “General Ramsey, we have met before. And it is my pleasure now to meet with the very famous General Grant.”
“Excuse me if I don’t shake hands, sir,” said Grant, nodding at his immobilized right arm. “Now permit me to be blunt; I wish to know why we have been summoned here.”
“It will be with great satisfaction that I tell you — indeed show you. If you will follow Mr. Davis.” The Swedish engineer explained as they walked. “I assume that both you gentlemen are acquainted with the steam engine? Of course, you will have traveled on trains, been many times on steamships. So then you will know just how large steam engines must be. This immense size has worried me in the construction of the new ironclads. These new ships are far bigger than my first Monitor, which means that to supply steam to engines that rotate the gun turrets, I must run steam lines about the ship. The lines are very hot and dangerous and therefore require thick insulation. Not only that, but they can be easily broken, and they are unsatisfactory in general. But if I generate steam for each turret engine, I will have created a mechanical monstrosity, with engines and boilers throughout my ship. I am sure that you see my problem. No, I thought, there must be a better solution.”
“Smaller, more self-contained engines to move the turrets?” Ramsey said.
“The very truth! I see that you are an engineer as well as a military man, General. That is indeed what I needed. Since an engine of this type does not exist, I, of necessity, had to invent one myself. This way, please.”
Davis showed them into a large workshop that was well lit by an immense skylight. Ericsson pointed to the squat metal bulk of a black machine. It was about the size of a large steamer trunk.
“My Carnot engine,” he said proudly. “I am sure that you gentlemen know the Carnot cycle. No? Pity. The world should understand this cycle because it is the explanation behind all the forces of energy and propulsion. An ideal cycle consists of four reversible changes in the physical condition of a substance, most useful in thermodynamic theory. We must start with specified values of the variable temperature, specific volume, and pressure the substance undergoes in succession—”
“Excuse me Mr. Ericsson,” General Grant interrupted. “Is that Swedish you are talking?”
“Svensk? Nej. I am speaking English.”
“Well, it could be Swedish as far as I am concerned. I can’t understand a word that you said.”
“Perhaps — if you were less technical,” Ramsey said. “In layman’s language.”
Ericsson drew himself up, anger in his eyes, muttering to himself. With an effort he spoke again.
“All right, then, at its most simple. A quantity of heat is taken from a hot source and some of it is transferred to a colder location — while the balance is transformed into mechanical work. This is how a steam engine works. But the Carnot cycle can be applied to a different machine. That machine is what you see here. My Carnot engine has two cylinders, and is much more compact than any steam engine which must rely on an exterior source of steam to run. Here, using a very volatile liquid I have refined from kerosene, I have succeeded in causing combustion within the cylinders themselves.”
Grant hadn’t the slightest idea what the man was talking about, but Ramsey was nodding agreement. Ericsson signaled to a mechanic who was oiling the engine with a long-spouted can. The man put the can down and seized the handle of a crank that was fixed to the front of the machine. He turned it, faster and faster, then reached over and pulled a lever. The engine burst into life with a thunderous roar, then it poured out a cloud of noxious smoke. Ericsson ignored the smoke, fanning it away from his face, as he pointed to the rear end of the machine at a rapidly rotating fitting. “Power, gentlemen,” he shouted above the din. “Power to rotate the heaviest turret in the biggest ship. And the end of the deadly steam lines.” He reached to pull the control lever back and the roar died away.
“Very convincing,” Ramsey said. Grant was less than impressed, but kept his silence. Davis, who left the workshop before the demonstration had begun, had returned with another man, well dressed, small, and rotund.
“Why, Mr. Parrott,” General Ramsey said, smiling broadly, “how very good it is to see you again. General Grant, this is William Parker Parrott, the eminent gunsmith.”
This General Grant could understand. “Mr. Parrott, this is indeed a pleasure. I believe that your weapons are the best in the world. God knows that I have fought and won many a battle with them.”
Parrott beamed with delight. “I shall treasure those words, General. Now let me show you why I asked Mr. Ericsson to invite you and General Ramsey here. Or rather why Mr. Ericsson and I have collaborated on an invention. It all began when Mr. Ericsson was visiting my office some time ago and saw on my wall a British patent application for a totally impossible invention.”
“As it was then designed,” Ericsson said. “But improving on the original is not impossible to men of genius — which is a distinction that Parrott and I share.” The inventor was never the one to hide his light under a bushel. “When I had finished my Carnot engine, I thought at once of the patent for the impractical steam wagon. Now, I said to myself, now it can be built. And between us we have done just that.”
He led them across the room to a bulky form draped with canvas. With a dramatic gesture he pulled away the cover. “There, gentlemen, a practical engine wagon.”
It was such a novel machine, so strange to the eye, that they could not take it in all at once. It appeared to be a triangular platform of sorts with spiked wheels on its two front corners, a single wheel at the back. The stocky black engine sat sideways across the device. A cogged wheel was fixed to the engine’s shaft. This, in turn, transmitted power to a heavy chainlike device, which, in turn, rotated another cogwheel on the shaft connecting the two front wheels. Behind the engine was a small seat facing some gauges and a tiller that was connected to the steerable rear wheel. The mechanic started the engine and stepped back. Parrott climbed proudly into the seat, worked some levers — and the machine rolled slowly forward. Using the tiller to move the rear wheel, he trundled slowly about the workshop, making a complete circle before he returned to the starting place and turned off the engine. Even Grant was impressed with the demonstration.
“Remarkable!” Ramsey said. “Strong enough to tow a heavy gun over rough terrain.”
“Yes, it can do that,” Ericsson said with a smile. “But it can do even more.” He signaled to the door, where two men were waiting. They went out and returned with a wheeled Gatling gun. With practiced movements they placed a ramp before the machine and rolled the gun up onto the platform between the front wheels.
“So you see, gentlemen, with a single addition the powered wagon becomes a mobile battery.”