My telescope is mounted in an apartment adjoining my cabin, with an elevated exposure, and has some extra contrivances for the convenience of adjustment, designed and constructed by myself. The instrument can be raised and lowered at pleasure, and is protected by a movable dome, which is easily laid aside by means of a couple of pullies. It is a good one, and for its size has remarkable power. I have been enabled to reach with it double stars of the sixth magnitude, frequently observing even Orion, with its beautiful double and multiple systems. I can easily discover with it the most distant planet Neptune, and by their progressive displacement, I have seen and recognized with it most of the asteroids. I can get with it a fine view of Jupiter, that magnificent planet fourteen hundred times larger than our Earth, and have observed the black spots upon its surface, and the transit of its moons. The grand spectacle of Saturn and its rings is brought to my observation with remarkable clearness. I have so frequently looked into the dismal caverns and upon the towering mountains of our satellite, the Moon, that its marks and bounds are as familiar to me as the neighboring hills. But life is short, and amid all this illimitable sea of worlds, I have fixed my attention upon but one, for that special study which my few remaining years will permit. The heavenly body which most engages my attention is, excepting our satellite, the nearest one to us, our neighboring planet Mars. I believe that body to be inhabited by beings in many respects like those of the earth. My conclusion is adduced from many known facts concerning it. Mars has an atmosphere like ours. Its density does not differ materially from the Earth. The heat it derives from the sun, possibly modified by atmospheric conditions, is quite likely the same as ours. It has zones of varying temperature, and seasons of summer and winter like the Earth. Its days are about the same length as ours. The ice and snow of its polar regions are plainly perceptible, and vary in arrears exactly in accordance with its changing positions and distances from the sun. From which we may infer, without a doubt, that its atmosphere contains moisture of the same chemical composition as ours, and is condensed into rain and snow as with us. There are striking points of difference, however, between Mars and the Earth. Its diameter is a little less than half that of our planet, and its surface is only about a quarter of ours, while its volume is but a seventh part of our globe. Furthermore, instead of a single satellite like ours it has two moons, which revolve in opposite directions around it, neither of which in point of size can be compared to ours.