"My investigations were commenced immediately after the first revelations made by M. Victorien Beaugrand. I collated all his statements. I analysed all his impressions. I seized upon all that Noël Dorgeroux had said. I went over the details of all his experiments. And in consequence of carefully weighing and examining all these things I did not come to the first performance at Meudon with my hands in my pockets, as a lover of sensations and a dabbler in mystery. On the contrary, I came with a well-considered plan and with a few working-implements, deliberately selected and concealed under my own clothing and that of some of my friends who were good enough to assist me. "First of all, a camera. This was a matter of some difficulty. M. Théodore Massignac had his misgivings and had prohibited the introduction of so much as the smallest Kodak. Nevertheless I succeeded. I had to. I had to provide a definite answer to a first question, which might be called the critical question: are the Meudon apparitions due to individual or collective suggestions, possessing no reality outside those who experience them, or have they a real and external cause? That answer may certainly be deduced from the absolute identity of the impressions received by all the spectators. But to-day I am adducing a direct proof which I consider to be unassailable. The camera refuses any sort of suggestion. The camera is not a brain in which the picture can create itself, in which an hallucination is formed out of internal data. It is a witness that does not lie and is not mistaken. Well, this witness has spoken. The sensitive plate certifies the phenomena to be real. I hold at the disposal of the Academy seven negatives of the screen thus obtained by instantaneous exposures. Two of them, representing Rheims Cathedral on fire, are remarkably clear. "Here then the first point is settled: the screen is the seat of an emanation of light-rays. "While I was obtaining the proofs of this emanation, I submitted it to the means of investigation which physics places at our disposal. I was not, unfortunately, able to make as many or as accurate experiments as I should have wished. The distance of the wall, the local arrangements and the inadequacy of the light emitted by the screen were against me. Nevertheless, by using the spectroscope and the polarimeter, I ascertained that this light did not appear to differ perceptibly from the natural light diffused by a white surface.