After breakfast Menni took me on a tour of our ship. First we went to the engine room, which occupied the entire lowest floor of the etheroneph at its flattened bottom. It consisted of five rooms, with one in the center and four others arranged around it, all of them separated by partitions. The huge engine stood in the middle of the center room. Round glass windows were set in the floor on all four sides around it. One was pure cyrstal, while three were of different colored glass. They were all about three centimeters thick and marvelously transparent, though at that moment we could only see a small part of Earth's surface through them. The main part of the engine was a vertical metal cylinder three meters high and a half meter in diameter. Menni explained that it was made of osmium, a very refractory precious metal resembling platinum. It was in this cylinder that the decomposition of the radioactive material took place. Its red-hot, 20-centimeter thick walls gave an indication of the enormous energy being released in the process. It was not very warm in the room, however, for the cylinder was encased in 40 centimeters of a transparent material that provided excellent insulation from the heat. The etheroneph was evenly heated by warm air conducted through pipes running off in all directions from the top of this case. The other parts of the engine attached to the cylinder — electric coils, accumulators, dials, and so on — were arranged in perfect order around it, and a system of mirrors enabled the mechanic to see all of them at once without leaving his seat...