This thought of communicating with the Martian by writing, did not deter me from using every effort to perfect my instrument, so that this might be done verbally, or that at least I might hear a voice and a language spoken on a world millions of miles away. Accordingly I gave the subject of sound-waves my best thought, and the next morning I had formulated clearly laid principles upon which to work. By these I hoped to make an instrument that would be the means of conversing with a Martian. I had come to the conclusion that the jumble of sound was caused by the prolonged vibration of the wires after each distinct wave from Mars was received, as the wires of a piano will vibrate long after they have been touched. With light-waves it was necessary to have a highly sensitive surface of the composition, capable of responding to many different vibrations, according to the light or shade of the object projected. This accounted for the success I met with upon adopting the coated wires, and I concluded thereupon that they were indispensable. But I now saw that the presence of wires in the composition, though successful with light-waves, was inimical to sound-waves, and it became evident that a firmer but highly sensitive surface was required. The film had not brought good results, either from sound-waves or light-waves, but, it will be remembered, there were wires running through it to give it rigidity, which, although necessary in my original experiments, must be avoided in connection with sound vibrations. Clearly my new film must not be rigid. I thereupon made a film of composition, as thin as possible, and stretched it upon the frame of my instrument, as a diaphragm behind the wires, hoping that the sound-waves would pass between the wires, and vibrate the diaphragm, which, being made of composition, would undoubtedly glow, but not more than the film had done. This, I concluded, would not interfere with the image on the wires, owing to the brilliancy of the latter. I was now hopeful of success, and anxiously waited for the day to close. Everything was in readiness by noon, and I had at least eight hours to wait before Mars would be in a position for wave contact. But now appeared an adversary with which I had not reckoned. Clouds began to gather, thin and fleecy at first, but growing heavier as the afternoon passed, until by evening the heavens were completely obscured. This was a condition that might last for several days, and the dread of it filled me with despair. How could I wait for days inactive, without seeing or even hearing from my friend in Mars?