But the matter was not to stop here. In 1831 it had been discovered by Faraday that when a piece of soft iron surrounded by a metallic wire was passed by the poles of a magnet, an electric current was produced in the wire, which could be exalted so as to give a spark; and upon this hint an apparatus has been constructed, consisting of an accumulation of powerful magnets and iron cores with surrounding coils. This apparatus, driven by steam-engines, and fitted with a subtle ingenuity of resource always tending to simplicity that seems a marked feature in the mind of the patentee, is, as we have said, at this moment at work, and very glorious it is to the eye of the observer; a piece of sunlight poured out upon the night. The chief point to be determined is its power over fogs. That any light will penetrate through some fogs is out of the question. The Sun himself can’t do it. But the artificial light that can hold out longest and pierce the farthest is clearly the light at all costs for the turning points in the great ocean highways. A success of this kind would create something of a revolution in a branch of lighthouse art on which a vast amount of ingenuity and even genius has been expended; that is, the apparatus by which the light should be exhibited. There may be divisions among scientific men as to the abstract nature and action of light, but sufficient of its secondary laws are known to make various arrangements in regard to the management of a generated light most valuable. The old plan known in scientific nomenclature as the Catoptric system is by reflection. Take a bowl of copper, something like a wash-hand basin, and having shaped it carefully into a parabolic curve, and then silvered and polished the interior, set it up on its side and introduce an argand lamp into it, so that the flame of the lamp shall be in true focus, and we have a reflecting apparatus. These may be multiplied in double and triple rows, and may be either placed upon flat faces, or curved to the circle, but a lamp in the centre of a reflector is the basis of the arrangement. If a light were put upon a rock in the ocean without a reflector, it would be seen dimly, but all round. Dimly, because the light, spreading in all directions, would be weak and diluted, but visible all round because there would be nothing to obstruct it. But put this light into a twenty-one inch reflector, and we have two distinct consequences;--one that we obstruct the radiation of all the rays except those that escape from the mouth of the reflector; the other, that we reflect into the same direction as the rays that are escaping all those we have obstructed from their natural radiation.