Page:The Music of the Spheres.djvu/229

 heat, the tumult on even our nearest star could never reach us; yet sound is such a laggard traveler compared with fleet-winged light, that light could cover the distance of 93,000,000 miles in less than 8 minutes while sound would require over 14 years to travel over the same space. Thus, even if we could hear the voices of these explosions, they would never coincide with the scenes enacted.

The bright yellow surface of the sun which every one sees, is called the photosphere or light-sphere. If strongly magnified through a telescope, this surface is seen to have a decided "mottled" appearance, like a layer of little clouds with dark spaces between, spread over the whole face of the sun. These are now known to be masses of calcium gas.

Practically all that is known of the physical constitution of the sun has been discovered through the study of the fine, dark lines in the solar spectrum. Through the aid of the spectroscope, many terrestrial elements have been discovered, among these being calcium, sodium, magnesium, potassium, aluminum, silver, iron, nickel, copper, zinc, tin, lead, hydrogen, oxygen and carbon. All these elements are either in the form of permanent gases or metallic vapors.

The photosphere or light-sphere lies below the chromosphere or color-sphere. Beyond the crimson color-sphere lies another envelope of very delicate light called the corona. This may only be seen at the time of total eclipse. It was once thought to belong to the moon but it is now known that the moon has very little atmosphere. Besides, the moon's black disk may be seen floating across this beautiful halo of light.

The corona has been described by those who have seen it, as having a "soft, pearly radiance" "tinged with green"; its form is quite irregular and varies at different times, extending from 1,000,000 to 3,000,000 and sometimes even 9,000,000 miles beyond the surface of the sun. In the eclipse of 1879 the streamers were