How amazing it is that this ponderous globe should be suspended in the fluid air, without any visible support, and upheld only by the sovereign will of its almighty Creator! His power, who “hangeth the earth upon nothing,” is inconceivably great; and the revolutions of this globe produce the most beneficial effects. The daily rotation of the earth causes the uniform succession of light and darkness; and its annual motion occasions the difference of the length of the days and nights, and the beautiful diversity of the seasons. Many pious Christians, who read the Scriptures to great personal advantage, but who are unacquainted with the science of astronomy, are apt to doubt the truth of the astronomical principles concerning the shape and motion of the earth, because, as Dr. O. Gregory judiciously observes, they think them contrary to divine revelation. Such persons would do well to consider for what purpose the Holy Scriptures were written, whether as a measure of faith, or as a rule to regulate our philosophical notions? Gassendus, though he does not give a direct answer to the question, has made the following very pertinent observations on the subject. “There are,” says he, “two sacred volumes, the one written, called the Bible; the other Nature, or the World; God having manifested himself by two lights, the one of revelation, and the other of demonstration; accordingly the interpreters of the former are divines; of the latter mathematicians. As to matters of natural knowledge, the mathematicians are to be consulted; and as to objects of faith, the prophets; the former being no less interpreters, or apostles, from God to men than the latter. And as the mathematician would be judged to wander out of his province, if he should pretend to controvert, or set aside any article of faith from principles of geometry; so it must be granted, the divines are no less out of their limits, when they venture to pronounce on a point of natural knowledge, beyond the reach of any not versed in geometry and optics, merely from Holy Scripture, which does not pretend to teach any thing of the matter.”
Mars is the first of the four superior planets in order from the sun, his orbit being immediately beyond that of the earth. He was called by the Greeks Αρης, the supposed god of war, which, says Parkhurst, comes from the Hebrew עריץ violent, destructive. Costard remarks, “This planet, I suppose, was called ערע Ara, ערץ Aretz, Αρης, and, in another dialect, מערץ Ma-aretz, or Mars, in a softer pronunciation, from his strong glowing brightness.” He is distinguished from the other planets by the red and fiery appearance, of his disk: whether his ruddy troubled color arises from a natural disposition to reflect the red rays of light best, or from a thick atmosphere attending it, is rather uncertain; but it is generally attributed to the density of his atmosphere.
“In larger circuit rolls the orb of Mars,
Guiltless of stern debate, and wasteful wars,
As some have erring taught: he journies on,
Impell’d and nourish’d by the attractive sun;
Like us, his seasons and his days he owes
To the vast bounty which from Phœbus flows.”
His figure, like that of the earth, is an oblate spheroid. His mean distance from the sun is 145,000,000 miles, and he travels round that common centre of gravity in about 687 of our days, or 1 year, 321 days, 22 hours, 18 minutes, 27 seconds, which is nearly equal to two of our years; and therefore his velocity in his orbit is at the rate of 55,000 miles an hour. He has likewise a rotation upon his axis, which is performed in 1 day, 39 minutes, 22 seconds. This was discovered by means of spots seen on his surface. Dr. Hook, in 1665, observed several spots, which, having a motion, he concluded that the planet revolved upon its axis. In 1666, M. Cassini saw several spots in the two hemispheres of Mars, which, by continuing his observations very diligently, he found to move from east to west, and to return in the space of 24 hours, 40 minutes, to their former situation. Whence both the motion and period, or natural day of this planet, were determined. In 1781, Dr. Herschell observed the spots of Mars very minutely, from the motion of which he has found his rotation upon his axis to be performed in 24 hours, 39 minutes, 21-2/3 seconds; and he says that there cannot be more than two seconds of uncertainty in this result. The different seasons will take place on this planet very much like what they are known to do upon our earth, with this difference, that the seasons there will be almost as long again as with us, on account of the time he takes in moving round the sun being nearly twice as long as our year. The diameter of Mars being 4,135 miles, he is about 2/11, or less than a fifth, and more than a sixth part as large as the earth; and if any moon attend him, she must be very small, for it has not yet been discovered by the best telescopes of our most eminent astronomers; if without a moon, walking his round in perpetual solitude, he must consequently want that division of time, which, from the moon’s revolution round the earth, is called a month.
From the greater distance of Mars in his orbit than our earth is, the inhabitants there will scarcely see Mercury, unless it be when he appears on the sun’s face, and passes over him like a dark spot, in the same manner as he sometimes does to us. Venus will to them appear somewhat similar to the appearances of Mercury to our earth, the apparent distance from the sun being nearly the same to them as Mercury is to us. Our earth to them, also, will be an inferior planet, or within his orbit, being nearer to the sun, in a way similar to what Venus appears to us, and will alternately be a morning or evening star; and our moon, which will always be seen to accompany her, when in a position to have the benefit of the sun’s light, will not be seen at a greater distance, than about a semi-diameter of the sun or moon from it.