Legatus Legionis: Book Two in the Gaius Claudius Scaevola Trilogy (2 page)

Then there were the two strangest prophecies: he would make a revolutionary discovery that was critical to understanding physics, and he would make a revolutionary engine that would eliminate the need for slavery. Then the peculiar addition: neither would change anything in his lifetime, but both were critical to his achieving success and averting some terrible disaster. How could that be? Then he was promised military success, he would win major battles and earn a triumph.

So far, prospects were not good. He believed he had been successful in command, but of the major incidents so far, only one had been a battle, and two he had resolved through diplomacy. Possibly it was more bluff and luck than diplomacy, but nevertheless . . . If he summed up where he had got to, he no longer had a military position; apart from his interpretation of contraries he had made no real progress on physics, while his engine was going nowhere quickly. Perhaps the one redeeming feature of his current situation was that while he had been with the
Cyrenaica
he had been far too busy to worry about either physics or engines; now he would have a lot of spare time.

His thoughts on physics were going nowhere, although to be fair, that was mainly because he had not really thought about it at all. Athene had required him to correct Aristotle's physics, and the correction would allow him to prove that the Earth was a planet that travelled around the sun. That seemed impossible, as shown by the fact that Timothy, his erstwhile teacher and now his friend, had provided proofs that the Earth was stationary and was not orbiting anything.

If his prophecy were real and not a dream, then the implication was that Athene knew the answer, and that Aristotle was wrong. Yet Timothy had provided proofs through physical observation that the Earth had to be stationary. Aristotle, the greatest mind ever, originally obtained these proofs and Aristotle would not be wrong, would he? According to Athene, Aristotle was wrong and if she were a Goddess, she should know. But if she were not a Goddess, then her knowing did not follow, unless . . . Unless what? Then there was the problem that, if she were a Goddess, why was she trying to persuade him to do . . . to do what? She had sent him on a mission, and from the way she told him in the dream, it was almost as if
she
did not know how to complete it either. Then there was her attitude; it was as if she needed him to succeed far more than he did.

So, assuming Aristotle was really wrong, what could he do? He could get around some of Aristotle's arguments, but Aristotle's physics had provided one point that seemed insurmountable: orbiting, or travelling in a circle, required continual force to change the direction. That force would have to be provided by the sun, and because the sun was always the same size, the Earth was always the same distance from it. That meant the Earth had to travel in a circle, which required the Earth to be continually falling towards the sun. Since heavier things fall faster than light things, the Earth should fall to pieces but it did not.

To make matters worse, it seemed quite obvious that the Earth was not moving. Suppose you were in a cart or chariot, and were being pulled by horses in full flight. Now, when the cart turned a corner, you tended to be flung against the side of the cart, or even worse, you could fall off the cart. Yet for the Earth to orbit, a continual force was required, the Earth would always be turning, and it would be travelling at speeds that made the fastest horses seem like somnolent snails. The problem was, people did not fall over or fall against walls, except when they were drunk.

That task was hopeless, which was why he had ignored it. Thinking about it was simply a waste of time, and added to which, as Timothy pointed out, even if he could falsify Aristotle's reasoning that did not mean that the Earth moved; it merely meant that Aristotle's reasoning was wrong. The problem was simple: to prove that Aristarchus was correct he had to find some observation that applied
only
if the Earth moved, for as Aristotle had pointed out, in logic there may be many hypotheses that could explain a fact, and such a fact did not prove any given hypothesis unless it were the only possible hypothesis.

One thing he was sure of was that movement had to be with respect to something else. Yes, there was the Sun, but that was no help. Even if you could prove the sun was not rotating and you could see the other side half the time, there was no way of telling it was the other side! Consequently, there was no way to prove the Earth moved around the sun. Except that whoever or whatever it was that called herself Pallas Athene said that he would. Well, if it were that important, she could have left a clue! She had a reason for why she hadn't too: she had said whether the Earth moved was unimportant; what was important was the method by which he proved that it moved.

Then there was the engine. He recalled that his last problem had been to work out how steam could generate power. It was not that steam did not have power, for he had previously seen the results of water heated in an enclosed vessel: the subsequent explosion was quite horrifying. The problem was how to control it, and make it do something useful.

His first thought had been to reverse the principle of a small hand water pump that he had seen once before. Instead of a hand pulling the piston up and down, sucking and pushing water, the steam could come and go, pushing a piston up and down. Simple! Except that it was not that easy. Valves could easily be designed to open when they were pushed from one side, and close when pushed from the other, so the water did what was asked of it, and a hand can equally push or pull. Steam, however, would only push. The problem with the entry valve was that the steam was always pushing, so closing it to stop steam entering was difficult. Worse, if the steam closed the exit valve while it was entering, it would push even harder while it was supposed to be exiting! What could he do?

After speaking on this to Timothy, he received the laconic reply, "Use geometry."

Great! How?

"Quite simple, really," Timothy shrugged. "You need two paths, and a means of switching."

"Explain!" a frustrated Gaius muttered. But Timothy was not that interested in going further. Conceptually, the task was done.

He saluted another cohort, then glanced out at the marching legion. Not far away was a small crossroads, and a number of carts were waiting patiently. Then, as one cohort passed through, a Centurion stopped the next cohort, and waved the carts through. That, Gaius realized, could be the principle. He needed valves that could be opened and closed, and he could see how to achieve that: he needed some form of controller to switch paths at the right times. A rocker arm would do that. The valve could comprise a single path with, say, a right angle in it, and it could switch between two positions. In one configuration it would connect the steam generator with the cylinder, and in the other, achieved by turning it ninety degrees, it would connect the cylinder with the exit route. That should work. The valve would comprise a cylinder with the path through it that moved tightly inside another cylinder with connecting paths to the steam, the piston, and the exit. That would be easy until, he realized, someone had to make this contraption, and join it to the various pipes.

If the piston drove a wheel, that wheel could drive the rocker arm, as it had to be in phase. The problem now reduced itself to working out how he could make levers pull or push one or more valves into one or the other position. He quickly realized that simply fixing the valve to a lever would not do, because most of the time the valve would be closed to everything. It needed to be fully open to steam through almost all the power stroke, and fully open to the exit through the venting stroke. After some thought, he settled on a rocker arm plus a lever. The rocker arm would have a pin, and the lever would permit the pin to slide up and down a space. Accordingly, when the lever reached close to one extreme of its path, it would pull the rocker arm, which in turn would move the valve one way; when it reached the other extreme it would push the rocker arm, which would push the valve to the other position. All he had to do then was get the timing right; that would be roughly calculated, but could be adjusted later by trial and error for finer tuning. If that did not work, an alternative might be a cam; a wheel that would rotate, but because of an asymmetry, such as a groove, or a different radius, would move a switch.

Now that he had defined the problem properly, there were so many possible solutions that he had a new problem: which of these were the most likely to work? He would think about this and design something, then make a model and see if he could make a lever from a wheel move a rocker arm between two positions on a regular basis with sufficient force to turn a valve.

* * *

Eventually, the last cohort was marching down the road, and Gaius could return to his tent. He changed into less formal clothing and sat down to an early lunch of bread, cheese and fruit, then he drank some water. Sooner or later he would have to pack up this tent and leave, but that could wait. His orders were to remain in Judea, which presumably meant proceeding to Caesarea. There was no hurry; he could get started tomorrow, and leaving it for tomorrow might save him effort as he understood that a few soldiers had been sent from Caesarea to assist him.

He had to find somewhere peaceful where he could be alone. There was an olive grove nearby; he would find some shade there, sit and think further on his invention. In the event, nothing came to him, but it was, nevertheless, very pleasant. For the first time in months he was not responsible for anything, and he intended to enjoy not doing anything, and taking a long time not doing it.

He was about to return to camp when he saw a man and a woman walking towards him, and from the way they had altered course after seeing him, and the woman had pointed at him, they were obviously looking for him. As he got up and they got closer, he recognized the woman: Rebecca, the Christian woman he had saved from being stoned for blasphemy by some Jewish fundamentalists.

"Greetings to you," he said, as they approached.

"Greetings," Rebecca replied. "
Legatus
, this is James, the brother of Jesus, and James, this is
Legatus
Claudius Scaevola."

"As it happens, I am no longer a
Legatus
," Gaius replied with a smile, "so I am afraid if you want something, I may not be able to help."

"I gather you were responsible for the extraordinarily large amount of money that was thrust upon us yesterday," James said. "We wish to thank you."

"You will thank me best by using it only for the benefit of the poor," Gaius replied.

"It will all be so used," James replied. "Why did you do that?"

"I chose you to distribute it because I thought you would be the most trustworthy for that purpose."

"What I meant was, why give it to the poor through Christians?"

"You think it was atonement for Romans crucifying your brother?" Gaius asked curiously.

"Was it?"

"Sorry if I disappoint you, but no, it wasn't."

"Good! I would only be disappointed if it were. But you haven't answered. Why?"

"Then this will probably disappoint you. I honestly don't have a good reason. I came across a group of Jewish thieves who were trying extortion on a caravan and a group of Roman auxiliaries who were probably also demanding money from the caravan for protection. I was really annoyed, but I didn't know what to do. Then that solution just came to me. It was the one solution in which nobody in the wrong could benefit, and the ones who did benefit were those who were completely innocent, at least on this matter, and who really needed help. I trust you to give it."

"And you didn't try to benefit yourself." This was a statement, not a question.

"Why would I?" Gaius said in a puzzled tone.

"That you ask that question is its own answer."

"You're going to try to convert me," Gaius smiled.

"No, I'm not," James shook his head. "There is no need to convert you, as you put it."

"You can't be both a priest and a
Legatus
," Rebecca added.

"My brother was a great teacher," James continued, "and he always insisted it's what you do that counts. The solution, as you put it, may have come to you, but it came from somewhere."

"And you know from where." This was also a statement.

"Where you think it came from is irrelevant," James shrugged. "What is important is that you listened."

"You must keep listening," Rebecca added. "There will be many more times . . ."

"I'm afraid you're wrong there," Gaius gave a harsh laugh. "My reward for bringing peace and stopping unlimited bloodshed was . . ."

"Your reverse will be temporary," Rebecca interrupted.

"You seem certain?"

"I am certain," she said. "If you keep listening to where your idea came from, you will do much good."

"I am a soldier," Gaius said in a slightly bemused tone. "A soldier's job involves killing."

"Yes, but what happens when you have won?" Rebecca asked.

"I see where you are going," Gaius nodded. "What I don't understand, though, is why you came to me?"

"You have done a good deed," Rebecca replied, "so I prayed for your soul."

"And?" Gaius asked impulsively.

"I received an answer," Rebecca said. "I was instructed to tell you that to find your own way, you must keep listening to the goodness in your heart and open your eyes so you will see all that is around you, open your mind so you can do something with what your eyes and ears provide, and when things seem to go bad, and they most definitely will, you must do what your heart tells you is right."

"I see," Gaius said, without any particular conviction.

"I was also told that you would doubt this," Rebecca continued, "but eventually you will see. In the meantime, you must listen. You should also do one more thing that the Master taught."