Chapter 10

The trip north was a little more promising. We flew over some lava fields with a few volcanic cones showing through. Undoubtedly, there were minerals down there that we could use, but we were not going to find them from the air. However, the trip was not wasted, since we now knew where we could search with a reasonable chance of success.

Of course, that still left the area near our cave to explore. We had been doing this sort of exploration for the last few years, but there had been nothing systematic about it. A few adventurous souls had taken short trips on foot or horseback to look around, but these had really been more vacations than serious efforts to find useful mineral deposits. This would have to change.

George worked out a search grid while I trained a few interested people in how to find what we needed. We had made some aerial photographs that served as maps, as one of the first projects for our earliest Zeppelins. George used these photos to plan out his search schedule. A few places looked particularly interesting, so prospectors were sent to those grids first. We would cover the whole area before we quit, but the most attractive were at the top of the list.

Enough people were interested that we could send out two five-woman teams to look over the two most interesting blocks. They were looking specifically for signs of iron, zinc, and mercury. Of course, the actual list of items of interest was longer than that, but those were the items at the top of the list of metals of interest. We knew that traces of iron would be found, expected zinc, and hoped for mercury. Anything else would be gratefully accepted.

A case of 12 CB (Citizen Band) radios had been included in our stores from Auburn, so one was issued to each of the prospecting teams and one was set up as a home base so that we could keep track of the progress each exploration team was making. A radio had been included with the Zeppelin flights, but it did not take long to get beyond range, so little use was made of the radios on those flights.

One of the boys, Ed, had gotten interested in the possibilities of radio, so he had been looking through the DVDs we had on the subject. That was where he discovered that much more range could be gotten from the base station if a full sized "beam" antenna was used instead of the "whip" antenna normally supplied with the radio. He was able to increase the range from a reliable eight klicks to a reliable 50 klicks. The range could be even greater under the proper conditions, especially if a beam was used at both ends of the circuit. I couldn't help laughing when I realized that Aerial had been the one to draw the copper wire used to connect to the antenna.

Holly led one of the exploration teams and Sue led the other. Both girls were somewhat competitive in nature, so I hoped that this would prompt them to make some useful discoveries. Sue made the first find worthy of note: she found zinc in quantities worth mining. It was easy to tell that Holly was disappointed that her team had been beaten out for the first useful find.

However, Holly had what might have been the last laugh, because her team found both iron ore and coal. If we could properly exploit her finds, Holly's team would have come in with the best job. If everything worked out the way it had the first time around, the steel would be more important than the brass from the zinc, but nobody could really predict that at this stage.

The two teams were called back in when they finished covering their assigned areas. They needed to rest and refit before taking on another trip of exploration. On their way home, Sue's team was attacked from ambush by a pack of animals about the size of the hyenas, but these animals hunted during the day. Everybody on the team was armed with crossbows and explosive bolts, so they had what they needed to protect themselves. Abbe was also carrying some hand grenades, and that turned out to be quite fortuitous.

The dogs gave the first warning, of course; where would we be without those faithful dogs? All of the women were reasonably alert, though they were all tired from being in the field for over two weeks. The actual number of attackers was never known, but the dogs and women managed to kill 16 of them in the first attack wave. The women had no trouble identifying enemy versus dogs because of the difference in size between the two.

The battle lasted only two or three minutes, because the second attack was broken up by Abbe's hand grenades. The attackers ran away, probably because of the noise of the explosions, but, whatever it was, there was no third attack.

There were only two fatalities among the team. Two of the dogs were killed by the attackers, and several others had received relatively minor wounds. The two heroic dogs were buried and their graves were marked. It was a greatly saddened, but highly alert team that made it the rest of the way home.

The Sterling Cycle engine was one of the problems that was holding up the launch of an effective airplane. We needed an engine that did not need continual attention by the pilot. Our Sterling engines were somewhat temperamental, possibly because of the lack of fine machining standards that we were still stuck with. That was why I was so pleased when Harry came to see me. "Adam, why don't we use jet engines to power our airplanes? They sure would be a lot simpler for the pilot to handle."

"I agree with that, but we have enough trouble with machining the parts for a Sterling Cycle engine. Just think of how much more difficulty we would have with a jet engine."

"Not necessarily. I was digging through the DVDs on jet engines and came across a very simple design: the pulse jet. It has almost no moving parts and does not need fine machining. In fact, it would be much easier to make than one of our Sterling engines."

"If the pulse jet is so good, why was it never used commercially back on Old Earth?"

"That's just it, the pulse jet is easy to build, but does not have the efficiency of the more complex engines. As far as I have been able to find out, it was never used in large numbers for anything but the German Buzz Bomb of World War 2. There, they were after the simplicity and low cost of the pulse jet, and the other concerns were not that important."

"OK, so we go with the pulse jet. Who would make one, and what fuel would it use?"

"That's easy to answer. If you ask Aerial to help me by making me some bronze sheet, I can make the jet. It would used bottled hydrogen for fuel, and we have plenty of that, with the ability to make more as we need it."

"OK, Harry, you have convinced me. How long will it take you to design a prototype?"

"I figured that you would agree, so I went ahead and did the design work. It should take me about a month to have a prototype built as soon as I get the sheet metal."

That problem was resolved easily, since I was able to divert some sheet metal from another job to the jet engine project. Harry was back to me in five weeks to report that the jet was ready for its demonstration. The slight holdup had been the machining of three valves which had been a bit more difficult to do than Harry had expected.

I canceled all other commitments for the day and followed Harry to his workshop. He admitted that this was not the first time he had fired up the jet, since he wanted most of the bugs out of it before his demonstration. There were a few minor things he still needed to do, but he assured me that he would not be afraid to fly with the current prototype.

Starting the engine was simplicity, itself. A fuel and air supply was already hooked up, so all he had to do was to open a valve and flip one switch. Suddenly, the workshop was filled with the most God-awful noise as the jet sprang into life. There was the distinctive rapid putt-putt-putt noise of the pulse jet firing, and the hard pull of the engine as it tried to jump off the mounting stand.