While thus discussing the details of our army organization, Astronomer Starbottle and his body-guard, Flathootly, arrived at the fortress, having safely escaped all perils in making a very hazardous journey. CHAPTER XLVIII. THE REPORT OF ASTRONOMER STARBOTTLE. I congratulated our couriers upon their safe return from a successful expedition. The astronomer made the following report of his journey: "Following our instructions to bear despatches to Egyplosis and Gnaphisthasia, and at the same time make such astronomical and meteorological observations as might be valuable to military operations in Atvatabar, we rose to a considerable height in the air after leaving the _Polar King_. We were still under the influence of the earth's revolution, moving with Atvatabar two hundred and fifty miles an hour from east to west. We found the atmosphere of equal density, no matter how high we ascended, showing it to be a continuation of the denser strata of the outer air pressing into the earth by way of the open poles. It fills the hollow shell of the earth as an elastic ball, pressing equally on every part of the interior surface. Notwithstanding its mobility, it partakes of the revolution of the earth, hence the particularly serene climate of Bilbimtesirol and the absence of trade-winds in the region of greatest motion, which corresponds to the torrid zone of the outer sphere. The only winds are local disturbances, sometimes excessively violent, caused by the irregularities of the earth's surface and the consequent unequal distribution of heat and cold. Besides the general serenity of the air there are other reasons why the interior planet is really the only true world where human flight is a complete success. "We found that at a height of fifty miles the gravity caused by centrifugal motion is exactly counterbalanced by the attraction of the central sun overhead. At a height of sixty miles, if the wings remain motionless, we perceptibly ascend with a slowly increasing motion toward the sun, while the centrifugal gravity slowly lessens, owing to the lesser circle of space traversed, the attraction of Swang as gradually increases, and nothing but the strength of our wings prevented our falling into the fires of the sun. "Our chief discovery was the fact that there exists a belt of air at a distance of between fifty and sixty miles above the earth, extremely cold, in which there is no weight, and all objects therein float, indifferent to the presence of the sun above or earth beneath. We saw a distant globe hanging in this region of very small size, and through the glass we could see mountains, rivers and seas thereon, but no traces of cities or human life.