A complete telegraphic system evidently connected all the strategic points upon Mars, so that, at a signal from the central station, the wonderful curtain could be instantaneously drawn over the entire face of the planet. In order to make certain that no part of Mars remained uncovered, we dropped down again nearer to the upper level of the smoke clouds, and then completely circumnavigated the planet. It was thought possible that on the night side no smoke would be found and that it would be practicable for us to make a descent there. But when we had arrived on that side of Mars which was turned away from the sun, we no longer saw beneath us, as we had done on our previous visit to the night hemisphere of the planet, brilliant groups and clusters of electric lights beneath us. All was dark. In fact, so completely did the great shell of smoke conceal the planet that the place occupied by the latter seemed to be simply a vast black hole in the firmament. The sun was hidden behind it, and so dense was the smoke that even the solar rays were unable to penetrate it, and consequently there was no atmospheric halo visible around the concealed planet. All the sky around was filled with stars, but their countless host suddenly disappeared when our eyes turned in the direction of Mars. The great black globe blotted them out without being visible itself. "Apparently we can do nothing here," said Mr. Edison. "Let us return to the daylight side." When we had arrived near the point where we had been when the wonderful phenomenon first made its appearance, we paused, and then, at the suggestion of one of the chemists, dropped close to the surface of the smoke curtain which had now settled down into comparative quiescence, in order that we might examine it a little more critically. The flagship was driven into the smoke cloud so deeply that for a minute we were again enveloped in night. A quantity of the smoke was entrapped in a glass jar. Rising again into the sunlight, the chemists began an examination of the constitution of the smoke. They were unable to determine its precise character, but they found that its density was astonishingly slight. This accounted for the rapidity with which it had risen, and the great height which it had attained in the comparatively light atmosphere of Mars. "It is evident," said one of the chemists, "that this smoke does not extend down to the surface of the planet. From what the astronomers say as to the density of the air on Mars, it is probable that a clear space of at least a mile in height exists between the surface of Mars and the lower limit of the smoke curtain. Just how deep the latter is we can only determine by experiment, but it would not be surprising if the thickness of this great blanket which Mars has thrown around itself should prove to be a quarter or half a mile."