To eliminate this element it would only be necessary to carry a certain quantity of lime-water, easily calculated, and by means of a fan or similar instrument to drive the whole of the air periodically through the vessel containing it. The lime in solution combining with the noxious gas would show by the turbid whiteness of the water the absorption of the carbonic acid and formation of carbonate of lime. But if the carbonic acid gas were merely to be removed, it is obvious that the oxygen of the air, which forms a part of that gas, would be constantly diminished and ultimately exhausted; and the effect of highly oxygenated air upon the circulation is notoriously too great to allow of any considerable increase at the outset in the proportion of this element. I might carry a fresh supply of oxygen, available at need, in some solid combination like chlorate of potash; but the electricity employed for the generation of the apergy might be also applied to the decomposition of carbonic acid and the restoration of its oxygen to the atmosphere. But the vessel had to be steered as well as propelled; and in order to accomplish this it would be necessary to command the direction of the apergy at pleasure. My means of doing this depended on two of the best-established peculiarities of this strange force: its rectilinear direction and its conductibility. We found that it acts through air or in a vacuum in a single straight line, without deflection, and seemingly without diminution. Most solids, and especially metals, according to their electric condition, are more or less impervious to it—antapergic. Its power of penetration diminishes under a very obscure law, but so rapidly that no conceivable strength of current would affect an object protected by an intervening sheet half an inch in thickness. On the other hand, it prefers to all other lines the axis of a conductive bar, such as may be formed of [undecipherable] in an antapergic sheath. However such bar may be curved, bent, or divided, the current will fill and follow it, and pursue indefinitely, without divergence, diffusion, or loss, the direction in which it emerges. Therefore, by collecting the current from the generator in a vessel cased with antapergic material, and leaving no other aperture, its entire volume might be sent into a conductor. By cutting across this conductor, and causing the further part to rotate upon the nearer, I could divert the current through any required angle. Thus I could turn the repulsion upon the resistant body (sun or planet), and so propel the vessel in any direction I pleased.