This does not exactly describe the phenomenon I witnessed and investigated, but it approximates as closely as I can manage. The chief points of difference are, that every flame casts a shadow, and this thing did not, unless a blur of light be a shadow; and furthermore, a flame may be seen even confronted with a stronger flame, and this thing I held was destitute of a perceptible outline. The pity was that I was then working without a single clue to any comprehension of the thing; and the greater pity is that though my knowledge became fuller, I am still ignorant of the action of the properties which made the thing visually impalpable. I can only guess at them. But I think I guess correctly when I conjecturally assert that it was surface coated with some essence which had the power to compel the great majority of the light rays to travel along its sides and surface and to resume their original direction afterwards. I do not pretend to understand how this essence could so interfere with and control the laws of light. But granting that it could, the explanation is a natural one. And though scientists may frown at me for advancing a theory which I am unable to substantiate, I prefer to incur their scorn rather than adopt the alternative--supernatural agency. I simply decline to believe in the supernatural. It is my profound conviction that nothing has ever happened on this planet, however mysterious and inexplicable, which has not been produced by a purely and perfectly natural cause. And the longer I live the more certain do I become that, deep and wonderful as our scientific acquaintance with Nature undoubtedly is, we have not yet even thoroughly explored the porch of her palace of secrets, her vast treasure-house of wonders. But I stray from my subject. It is my present business to relate events, not to discuss their basic principles.