Immediately adjacent to Phor Tak's laboratory was a well equipped machine shop and here Nur An and I labored for weeks utilizing the services of a dozen slaves until we had succeeded in constructing what I am sure was the most remarkable looking airship that it had ever fallen to my lot to behold. Briefly, it was a cylinder pointed at each end and closely resembled the model of The Flying Death. Within the outer shell was another smaller cylinder; between the walls of these two we placed the buoyancy tanks. The tanks and the sides of the two envelopes were pierced by observation ports along each side of the ship and at the bow and stern. These ports could be completely covered by shutters hinged upon the outside, but operated from within. There were two hatchways in the keel and two above which led to a narrow walkway along the top of the cylinder. In turrets, forward, and aft were mounted two disintegrating ray rifles. Above the controls was a periscope that transmitted an image of all that came within its range to a ground glass plate in front of the pilot. The entire outside of the ship was first painted the ghastly blue that would protect it from the disintegrating ray rifles of Jahar, while over this was spread a coating of the compound of invisibility. The shutters that covered the ports, being similarly coated, the ship could attain practically total invisibility by closing them, the only point remaining visible being the tiny eye of the periscope. Not possessing sufficient technical knowledge to enable me to build one of the new type motors, I had to content myself with one of the old types of much less efficiency. At last the work was done. We had a ship that would accommodate four with ease and it was uncanny to realize this fact and yet, at the same time, be unable to see anything but the tiny eye of the periscope when the covers were lowered over the ports, and even the eye of the periscope was invisible unless it was turned in the direction of the observer. As the work neared completion I had noticed that Phor Tak's manner became more marked by nervousness and irritability. He found fault with everything and on several occasions he almost stopped the work upon the ship. Now, at last, we were ready to sail. The ship was stocked with ammunition, water and provisions, and at the last minute I installed a destination control compass for which I was afterward to be devoutly thankful. When I suggested immediate departure, however, Phor Tak demurred, but would give me no reason for his objection. Presently, however, I lost patience and told the old man that we were going anyway whether he liked it or not. He did not fly into a rage as I had expected, but laughed instead, and there was something in the laugh that seemed more terrible than anger. "You think I am a fool," he said, "and that I will let you go and carry my secrets to Tul Axtar, but you are mistaken."