“I can claim but little part in the work,” Foedric responded, “but it is this. Our ears report to our brain the air waves until they reach a frequency of forty thousand in a second, and we call the sensation sound. When the vibrations of the ether are more rapid than that, we have no sense with which to receive the impression until they reach the great number of four hundred million millions in a second. Then they affect the eye and produce red light, and as they increase still more the color becomes orange, then yellow, green, blue, and violet. Perhaps your limitations are not the same as ours, but our scientists are trying to discover some means by which we can arrest and make use of a small part at least of those waves which strike our bodies at a frequency between forty thousand and four hundred million millions. It is still an unsolved problem, this search for another sense, and we are now looking forward for help in the task to the studies of the civilization represented in our comet.” All this time we were rising slowly but hardly realizing it, being filled with that peculiar sensation, incident to balloon journeys, by which we could almost believe we were remaining about in the same place and the solid ground was falling away from us. Now Foedric increased our speed and showed us how easily he could sail in any direction and at any rate he pleased, explaining to us the mechanism by which we were upheld and propelled, and also the way in which the current of electricity was generated and applied. They certainly had a wonderful method of producing great power with little weight, and the doctor eagerly drank in the information in regard to it, as if for future use. It was charming. The atmosphere was as clear as crystal, the air balmy and the motion delightful, and if the Martians, with their purer nature and keener senses, enjoyed the trip that morning more than we earth-dwellers did, then their capacity for enjoyment must have been beyond ours. The ship seemed to be under perfect control; there was nothing uncertain in her movements, and as we went sailing along without fear of harm, in the very poetry of motion, the doctor and I realized over and over again that we had much to learn in this method of navigation. Now we were riding at a good height, and our vision could take in a wide expanse of land and water. The peculiarity of the surface of Mars was noticeable, the seas being long, narrow inlets, as it were, running through or between winding strings of land, a decided contrast to the great oceans and noble continents of our mother earth. It seemed to me that this was much to the advantage of the earth, and so I was bold enough to say: