"Clouds were floating! And, because of the fact that clouds were floating on the horizon, the pictures on the screen grew less distinct or even vanished altogether. It may be said that this was a coincidence. On three separate occasions, when the film lost its brilliancy, I turned towards the horizon: on each occasion clouds were passing. Could three coincidences of this kind be due to chance? Can any scientific mind fail to see herein a relation of cause and effect or to admit that, in this instance, as in that of many visions previously observed, which were disturbed by an unknown cause, the interposition of the clouds acted as a veil _by intercepting the projection on its way_? I was not able to make a fourth test. But that did not matter. I had now advanced so far that I was able to work and reflect without being stopped by any obstacle. There is no such thing as being checked mid-way in our pursuit of certain truths. Once we catch a glimpse of them, they become revealed in their entirety. "At first, to be sure, scientific logic, instead of referring the explanation which I was so eagerly seeking to the data of human science, flung me, almost despite myself, into an ever more mysterious region. And, when, after this second display, I returned home--this was three hours ago at most--I asked myself whether it would not be better to confess my ignorance than to go rushing after theories which suddenly seemed to me to lie beyond the confines of science. But how could I have done so? Despite myself I continued to work at the problem, to imagine. Induction fitted into deduction. Proofs were accumulating. Even as I was hesitating to enter upon a path whose direction confounded me, I reached the goal and found myself sitting down to a table, pen in hand, to write a report which was dictated by my reason as much as by my imagination. "Thus the first step was taken: in obedience to the imperious summons of reality, I admitted the theory of extra-terrestrial communications, or at least of communications coming from beyond the clouds. Was I to think that they emanated from some airship hovering in the sky, beyond that cloud-belt? Leaving aside the fact that no such airship was ever observed, we must remark that luminous projections powerful enough to light the screen at Meudon from a distance of several miles would leave in the air a trail of diffused light which could not escape notice. Lastly, in the present condition of science, we are at liberty to declare positively that such projections would be quite incapable of realization.