Venus, at the distance of 68 millions of miles, completes her revolution in 224 days.
Earth, on which we live, at the distance of 95 millions of miles, performs its period in one year.[[4]]
Mars, at the distance of 145 millions of miles, in little less than two of our years.
Jupiter, at the distance of 494 millions of miles, in near 12 years.
Saturn, at the distance of 906 millions of miles, in about 30 years.
Georgian, discovered a few years since by Dr. Herschell, performs its period at the distance of 1812 millions of miles, in about 83 years.[[5]]
Pupil. What proportion does the earth bear in magnitude to the other planets?
Tutor. The earth is fourteen times as large as Mercury, very little larger than Venus, and three times as large as Mars. But Jupiter is more than fourteen hundred times as large as the earth; Saturn above a thousand times as large, exclusive of his ring; and Georgian eighty-two times as large.
Pupil. Have you any thing else, Sir, to remark concerning the planets?
Tutor. There are several other things I intend to make you acquainted with, namely, their nature, appearances, motions, &c. At present I shall only say, that Mercury and Venus are called [[6]]inferior planets, their orbits or paths described in going round the sun, being within that of the earth; and the other four, whose orbits are without the earth’s orbit, [[7]]superior planets.