The foregoing enumerated astronomical phenomena are some of the facts tending to confirm and elucidate Symmes's theory. They all have been long known to exist; yet I have never heard them accounted for to the satisfaction of my mind. Indeed, I believe some of them never was attempted to be accounted for in any manner whatever. I would, therefore, request the reader, who may deign to give the subject a serious thought, to reflect, that if all the celestial orbs are entire round globes, as the old theory considers them to be, on what principles, or in what manner, could they present the various appearances which I have enumerated? Why should the horns of Venus assume different shapes? What would make the appearance of belts on Jupiter? Or rings and concentric circles at the poles of Mars? And, finally, in what position could a round solid globe be placed, to exhibit the rings of Saturn, revolving with different velocities, as it respects each other, and spaces appearing between them and the body of the planet, through which stars, millions of miles beyond, can be distinctly seen? These are phenomena I should like to hear explained. On the principle of concentric spheres, they can all be accounted for in a most satisfactory manner. They appear perfectly plain and intelligible. What was thought to be involved in inexplicable mystery, and mid-night darkness now perfectly accords with the established laws of nature, and can be understood by the most ordinary capacity. FOOTNOTES: [4] Physical World, p. 42.――Adam's Philosophy, vol. 4, p. 206; Philadelphia, 1807. [5] "Dr. Herschel has observed a faint illumination in the unlighted part of the planet Venus, which he ascribes to some phosphoric quality of its atmosphere." Editor's note to Adams' Philosophy, vol. 4, p. 204, Philadelphia, 1807. _Quere_――Might not such an appearance be accounted for as rationally, by supposing the rays of the sun to shine or be reflected, through one of her polar openings, and fall on the verge of the sphere at the opposite polar opening? CHAPTER V. _The Theory of Concentric Spheres, supported by arguments drawn from Terrestrial facts; such as the migration of animals to and from the arctic regions, and from refraction, and the variation of the compass, observed in high northern latitudes._ I would now advert to a few of the known terrestrial facts, which have a tendency to support the theory advanced by Captain Symmes; such as the migration of animals, including beasts, birds, and fishes, in the arctic regions; and from refraction, and the variation of the compass observed in high northern latitudes.