Equally dependent are the seven other planets which, with the earth, whirl in elliptical orbits about this source of heat and light. "The Sun the seasons of the year supplies And bids the evening and the morning rise; Commands the planets with superior force, And keeps each wandering light to his appointed course." --_Lucan's Pharsalia._ The planets are sometimes called the "family" of the sun, although his family also includes the retinue of each planet, which in the case of six of them at least, consists of from one to ten moons. Our sun is no different than thousands of other stars in the sky; is it likely that our star alone of all the countless millions which shine in our universe, should be the only one to possess this additional charm of maturity? One looks far out in the darkness to the hosts of radiant stars--then wonders--how many stars have flocks of planets--how many travel alone? THE SURFACE OF THE SUN Compared to a point of starlight, the disk of our "day star" looks most exceedingly huge, and this at a distance of 93,000,000 miles. One is therefore not quite so surprised to learn that this great sunball, which rests like the hub of a wheel in the center of the solar system, has a diameter of 886,000 miles. The 8000 miles which measures across the earth seems quite inconspicuous when compared with such a diameter as this. Completely covering the sun's surface is a mass of intensely hot crimson gases. These gases are like a turbulent upper atmosphere with a depth of 5000 to 10,000 miles. Raging and seething in long tongues of flame, they swirl up for thousands of miles above the surface, or are thrown far above it in titanic explosions. Formerly, these burning gases could only be seen at the time of total eclipse when the black disc of the moon passed in front of the glaring face of the sun leaving only the red flames licking out beyond the dark edge. The invention of the spectroheliograph now makes it possible to photograph these projections when the sun is shining. One should never try to see them by looking at the sun unless the glare is shut off either by the moon or by artificial means, for the sun is so unbearably brilliant that the eyesight of an observer would soon be ruined. [Figure 133: SOLAR PROMINENCES. Huge flames ejected from the surface of the sun, photographed at Yerkes Observatory with the Rumford spectroheliograph attached to the 40-inch refractor.]