One of the exterior planets of the solar system, and the largest; revolves in an orbit outside that of the asteroids, at a mean distance from the sun of 480 millions of miles, completing its revolution round the sun in 4338 days, and taking 10 hours to revolve on its own axis; it is surrounded by belts considered to be openings in the cloudy atmosphere which invests it, and is accompanied by four moons, all nearly of the same size but at different distances, and with different periods of revolution round it; it is in volume 1300 times larger than that of the earth, while its weight is only 300 times that of the earth, is therefore less than one-fourth of the density of the earth.