Page:The fairy tales of science.djvu/213

Rh the dimensions, gauging as it were the contents, and weighing as in a balance the mass, not of our earth alone, but of all the other planets, and of the great sun himself.

Thus we know that the equatorial diameter of our globe is about 7926, the polar diameter 7900 miles; that our earth revolves round its axis with a velocity of nearly 12 miles in a minute, and that it moves in its orbit round the sun at a rate of more than 1000 miles a minute; that its distance from the sun is 95,000,000 miles.

The moon, the satellite of the Earth, is distant from it some 240,000 miles, and revolves round it in $27 1⁄2$ days; its diameter measures only 2180 miles.

Of the other planetary bodies, some are considerably larger, some smaller, than our earth. The largest of all, the brightest among them, is Jupiter, with a diameter of about 88,000 miles, and a bulk 1300 times that of the Earth; owing to his inferior density, his mass is, however, only upwards of 370 times that of our globe. Perpetual spring reigns on this King of Planets. Jupiter is attended by four satellites or moons, with the exception of one, each of them larger than our moon, which revolve round him from west to east. His distance from the sun is 485,000,000 miles; his revolution round the great centre of the planetary world occupies 12 years. The next in size is Saturn, with a diameter of 79,000 miles, and accordingly about 1000 times larger than the Earth; he is 890,000,000 miles