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Across the Zodiac by Percy Greg

With the receptacle or apergion

five smaller bars, passing through

the roof and four sides, connected, like the main conductor, with the receptacle or apergion, but so that they could revolve through a much larger angle, and could at any moment be detached and insulated. My steering apparatus consisted of a table in which were three large circles. The midmost and left hand of these were occupied by accurately polished plane mirrors. The central circle, or metacompass, was divided by three hundred and sixty fine lines, radiating from the centre to the circumference, marking as many different directions, each deviating by one degree of arc from the next. This mirror was to receive through the lens in the roof the image of the star towards which I was steering. While this remained stationary in the centre all was well. When it moved along any one of the lines, the vessel was obviously deviating from her course in the opposite direction; and, to recover the right course, the repellent force must be caused to drive her in the direction in which the image had moved. To accomplish this, a helm was attached to the lower division of the main conductor, by which the latter could be made to move at will in any direction within the limit of its rotation. Controlling this helm was, in the open or steering circle on the right hand, a small knob to be moved exactly parallel to the deviation of the star in the mirror of the metacompass. The left-hand circle, or discometer, was divided by nineteen hundred and twenty concentric circles, equidistant from each other.
The outermost, about twice as far from the centre as from the external edge of the mirror, was exactly equal to the Sun's circumference when presenting the largest disc he ever shows to an observer on Earth. Each inner circle corresponded to a diameter reduced by one second. By means of a vernier or eye-piece, the diameter of the Sun could be read off the discometer, and from his diameter my distance could be accurately calculated. On the further side of the machinery was a chamber for the decomposition of the carbonic acid, through which the air was driven by a fan. This fan itself was worked by a horizontal wheel with two projecting squares of antapergic metal, against each of which, as it reached a certain point, a very small stream of repulsive force was directed from the apergion, keeping the wheel in constant and rapid motion. I had, of course, supplied myself with an ample store of compressed vegetables, preserved meats, milk, tea, coffee, &c., and a supply of water sufficient to last for double the period which the voyage was expected to occupy; also a well-furnished tool-chest (with wires, tubes, &c.). One of the lower windows was made just large enough to admit my person, and after entering I had to close it and fix it in its place firmly with cement, which, when I wished to quit the vessel, would have again to be removed.

Of course some months were occupied in the manufacture of the different portions of the vessel and her machinery, and sometime more in their combination; so that when, at the end of July, I was ready to start, the opposition was rapidly approaching. In the course of some fifty days the Earth, moving in her orbit at a rate of about eleven hundred miles [4] per minute, would overtake Mars; that is to say, would pass between him and the Sun. In starting from the Earth I should share this motion; I too should go eleven hundred miles a minute in the same direction; but as I should travel along an orbit constantly widening, the Earth would leave me behind. The apergy had to make up for this, as well as to carry me some forty millions of miles in a direction at right angles to the former--right outward towards the orbit of Mars. Again, I should share the motion of that particular spot of the Earth's surface from which I rose around her axis, a motion varying with the latitude, greatest at the equator, nothing at the pole. This would whirl me round and round the Earth at the rate of a thousand miles an hour; of this I must, of course, get rid as soon as possible. And when I should be rid of it, I meant to start at first right upward; that is, straight away from the Sun and in the plane of the ecliptic, which is not very different from that in which Mars also moves. Therefore I should begin my effective ascent from a point of the Earth as far as possible from the Sun; that is, on the midnight meridian.

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