YOUR heart has been uplifted many a time by the glory of the rainbow, in the full light of day. I am going to introduce you now to a rainbow in the darkness of the night.
When seated with a crystal in the dark, a weak-sensitive sees nothing more at its two poles than a greyish, ill-defined cloud, a dull luminosity in the midst of the general night. A medium-sensitive draws a distinction: to him the brightness at one of the poles is bluish grey and blue, and at the other yellow and yellowish-red, corresponding with his own right and left hands. Finally a sensitive of higher degree recognizes that neither the blue nor the yellow is a simple colour, but that within it in each case other tints of all sorts—green, red, orange, violet—dart in and out of each other, and that each of the polar flames, when more narrowly observed, presents a polychrome appearance, always understanding this, however, in the sense that what we have just referred to are secondary shades, subordinate flecks of colour, in the general blue of the one pole and the general red of the other.
It was a sensitive naval pensioner, Frederick Weidlich, who first drew my attention, in February 1846, to the fact that these colours did not always play in and out of each other in this restless way, but that they lay over each other in repose, and took up a regular order, when not disturbed and mingled together by the current of air caused by my movements and breathing. And when I enquired as to the order they took up, I learnt that red, clouded by a deal of smoke, always took up the lowest place, and that over it first reddish-yellow, then saffron-yellow, then pale-yellow, on that finch-yellow, and then green appeared, that the latter shaded into blue, first a light-blue and then a dark, and that on top of all appeared a violet-red, which finally lost itself in smoky vapour, and that the whole was intermingled with a great number of tiny, brightly luminous sparks or little stars.
What I learnt for the first time from this man I was told subsequently by numerous sensitives in thousands of experiments made by night. Now, what else is this than the colour arrangement of the prismatic spectrum? The phenomenon of a rainbow of light in absolute darkness—what a marvellous sight! All high-sensitives described it to me as the most beautiful they had ever looked upon in their lives.
I set up a strong rod-magnet vertically on end, with its southward pole uppermost; a reddish tint dominated all the rainbow colours that layered themselves over it in repose. I reversed it, setting its northward pole uppermost, and a bluish colouration lay upon the dulled-off bow. The section of the rod at the poles was a square inch. In order to narrow this surface, I put a pointed iron cap upon it; the emanation of light became thinner, more luminous and longer, but the rainbow order of the colours remained constant.
Instead of the single-pointed cap, I next set an iron cap with two peaks upon it: lights now jutted out of both, but quite a blue light from one of them, and a yellow-red light from the other. Finally I put a four-peaked cap on it, and now each peak showed a differently coloured body of light; the first had a small blue flame, the second a yellow, the third a red, the fourth a whitish grey: all four stood straight up vertically, side by side, from the four corners of the magnet-rod. I had thus succeeded in separating some of the colours of this mysterious iris, and setting up each independently, so to speak, of the others.
When I turned the rod slowly round on its vertical axis, the colours did not go along with it, but each kept its own place, and when the peak with the originally yellow flame came to the spot previously occupied by the peak with the blue flame, the yellow had passed over into blue, the blue into grey, the grey into red, and so forth. The colours thus were not dependent on the rod alone, but stood in connection with some other exterior condition. The meaning of this was soon discovered: it was the quarters of the globe that influenced the colours of the rod. The blue light kept always on the peak that was directed towards N., the yellow on that towards W., the red on that towards S., and the grey-white on that towards E. I might turn the rod round with its four peaks as I chose, the colours never deserted their spot, but maintained the same position with one another in respect to the same quarter of the heavens.
Instead of the four upright peaks, I then fixed a four-cornered plate of iron with a square foot of surface lying horizontally on my rod-magnet. It had scarcely lain on the pole when coloured lights streamed out horizontally from all its four corners, just as the vertical lights had proceeded from the four peaks. When I turned the plate round a half-quadrant, the mixed colours presented themselves at the four corners, at N.W. green, at S.W. orange, at S.E. grey-red, and at N.E. violet.
Upon this I had a hollow sphere of iron made, so large that I could not quite embrace its circumference with both my arms, and suspended it, hanging freely, by a silken cord in the midst of my dark chamber. Passing right through its centre I fixed a vertical iron rod, twined round with six coatings of copper wire, which I could connect with a Smee and Young's electric battery of zinc and silver plates. Nothing of this was visible exteriorly. At the moment I converted the iron rod into an electromagnet my sensitives saw the suspended sphere emerge from the darkness in multi-coloured light. Its whole surface shone gaily with all the colours of the rainbow. The segments turned towards N. were blue from pole to pole, those towards N.W. green, those towards W. yellow, towards S.W. burnt yellow, towards S. red, towards S.E. greyish-red, towards E. grey, and towards N.E. a red stripe, with a recurrence of the blue. The colours visibly formed fine lines one beside the other, separated in each case by a darker line. The whole sphere was enveloped in a fine, luminous, englobing body of vapour.
The upper, odnegative half had at all points a more bluish sheen dominating its other colours, and the lower odpositive half one more inclined to red. Right on top, on the spot where the northward pole of the electromagnet was situate, a column of light, passing into blue, mounted to the height of a hand over the sphere, then bent back on all sides like an opened umbrella, and streamed down round about the sphere, at a distance of two to three inches from it. From the other pole, the southward one underneath, proceeded a similar bunch of flame, bending up round the sphere with a reddish light. They both became threadbare and lost before reaching the equator of the sphere.
A light is thrown on the matter when I say that my intention was to set up by means of this sphere a terrestrial globe according to Barlow, that is a small sphere in suspension, shaped like the earth, with a north and a south pole, equipped with the magnetic forces proper to it, and applied to the touchstone of the od-light. It is seen in fact that the results obtained resemble to a surprising degree those of the Northern Lights and the Southern Lights of our planet. More detailed resemblances than are here permissible to the demonstrator are obtainable by further parallelizing, and in such perfection that the hypothesis of the Northern Lights being positive od-light is one that has every probability in its favour.