Chapter 26

Charles and Flower of Spring were ready to begin the distillation process as soon as they got the crude oil unloaded. They had found that the distillation process delivered several different "fractions" as it was boiled at different temperatures. As the lower boiling components came off the oil, the mass left in the pot became more and more viscous. Finally, they reached the point where nothing more was coming from the pot, so they dumped it before it could cool down and solidify.

Part of their problem was the inability to measure the temperature accurately. They were using a bi-metallic leaf spring as a thermometer; it worked because iron and copper expand at different rates when they are heated. They were using a Celsius temperature scale, so they had the low temperatures pretty accurately calibrated, but the higher temperatures were merely scaled from the lower known values. At least, the distillate fractions came off at pretty distinct intervals of temperature, so they had a workable system.

Charles only had to make minor adjustments in his engines to make "Fraction D" work quite well as a substitute fuel for the animal fat. In fact, if anything, the engines ran with a little better fuel efficiency. With a little experimenting, Charles found that he could mix in the animal fat up to 25% into Fraction D without having to make any adjustments in the current fuel feed system.

They had to have more metal! There was enough copper and tin available if they could just mount the effort to get it. But they were back to the problem of not enough manpower. They were up against the roadblock of manual labor. If they had machines to do it, perhaps they could get at the ore in sufficient quantities.

They had reached the level of technical sophistication that they could now work with copper ore, not just with the raw metal. Charles asked a couple of his engineers to see what they could come up with in the way of mining machinery. The engineers came up with two possible designs: a bucket-brigade that scratched at the mine face and an auger that drilled into the mine face. They had no way of knowing which would be the better design, and Charles thought that they showed equal promise. In a fit of compromise, Charles told them to build one of each, since they needed a machine for each mine, anyway. They'd try both machines at both mines and see which one was better.

A lot of design work was required before the machines could be built. One of the things that had to be "invented" was the engineering science of hydraulics, since pure mechanical linkages were not flexible enough. At least, they could use bronze for their mechanical parts, since it did not rust like steel did. Also, they could use water as their hydraulic fluid; it was much less compressible than the oil fraction they had, and it would be some time before they had the means to make synthetic hydraulic fluid.

Arbitrarily, they build the auger drill first, since it was a little bit simpler mechanically. It bored a 3-foot diameter hole, and it was tested in the home caverns to look for more hollows where people could live. They did find one, but the main success was the proof that the auger drill did work. It was transported to the copper mine and tried out there. They needed copper in better than a 10 to 1 ratio to tin, so the copper mine needed to be mechanized first.

The auger drill worked and production immediately rose by a factor of six. At this rate, they would soon have enough bronze to run a spur track to the copper mine. This prototype gave the engineers several ideas for improving the auger drill, but Charles wanted to test the other idea before they spent a lot of time and resources working on the auger. The auger was left to work on the copper mine while the engineers adjourned to the shop to build the other machine.

The second machine consisted of a series of teeth shaped with attached buckets and all fastened to a continuous belt which ran over a main drive sprocket and the necessary idler sprockets for support. The machine worked by dragging a toothed bucket against the wall and chipping off some rock which was conveyed in the bucket back to a collecting hopper in the rear of the machine. This machine had the advantage of making a rectangular hole as wide as two men and as high as one man when he was standing, thus it could remove more earth and rock in one step than the auger could, but it could not work quite as fast as the auger.

The upshot was that the second machine could remove in one slow pass what the auger required four passes to do, though each pass was done more quickly. Overall, the bucket-brigade machine was faster at overall tunneling than the auger, but it had more maintenance problems. Charles decided that it was a write off in performance and maintenance, but the auger/drill was easier to build, so that was what they would standardize on until further notice. The bucket-brigade machine was shipped to the tin mine to work while additional, improved auger drills were built. They built four of the improved auger drills, three for the copper mine and one for the tin mine.

By the end of two years, they were into heavy production of copper and tin, resulting in plenty of bronze for their many commitments to customers and for their own use. In another year, they had installed spur tracks to both mines and were building up a healthy stockpile of rail in hope of soon running a track to Texas Lake to pick up oil.

The flights of The Cactus Flower had been so successful in exploring to the east that Doug wanted to send out similar flights to look over the whole continent, and, eventually, the whole hemisphere. Two more flying machines were constructed, The Evening Star and The Mist of the Mountains. They stopped before they got around to The Big Tits.

Because of the danger inherent in such a long mission, the two new ships were sent together to see what useful could be found south of Mexico. By this time, they had managed to get a radio system working, using spark transmission of Morse code. Each ship was equipped with a radio so that they could talk to each other and back to base. Doug selected a medium frequency band for the two ships to use for communicating with each other, and a different medium frequency and a high frequency for use in communicating with Doug's Town. The antenna was simply a trailing wire dropped from the gondola; they flew high enough that the antenna didn't snag anything on the ground. After a few short practice trips, the expedition was ready to travel south.

The two ships left with a big send-off, which included admonitions from parents for their children to be careful and warnings not to talk to strangers. Doug couldn't help laughing, who else were they going to talk to? The ships were loaded with the usual supplies and potential trade goods. Doug had included a list of things that he was interested in, and told them to be on the lookout for anything that might be useful. Doug wanted them to go as far south as they could, but not past the Isthmus of Panama, on this trip. They were to turn around and head for home if they ran into anything they could not handle.

Each airship had a captain, a navigator/radio operator, an engineer, and a pilot, and they were all cross-trained in the other skills. There were two men and two women on each airship, and the women were hoping to be pregnant by the time they returned home. Doug's people were still sticking to that custom that a woman had to have a child or to be pregnant before she could marry. Though they had never heard of the concept, these would shortly be the first eight members of the Mile-High club.

The captain of the Evening Star was also the leader of the expedition, but everybody else on the two airships had a say in all major decisions, except in an emergency—then the ship's captain was undisputed boss. For convenience, each person had taken a temporary name for the voyage, such as Star Captain, Mist Captain, Mist Pilot, Star Engineer, etc.

The airships took off and climbed to 1,000 feet. They followed the railroad track south until they ran out of track to follow. They had a few miles to go before they reached unknown territory, but they went on alert status, anyway, because there was little experience in flying this far south and no one had any idea of what to expect from wind or weather. As a safety precaution, they planned to travel at a minimum altitude of 1,000 feet unless they saw something that warranted closer examination.