Page:Popular Science Monthly Volume 1.djvu/158

148 these are termed faculæ, and are, in fact, the opposites of the solar spots. They are devious, undulating, shining ridges, like irregular ranges of snowy mountains, and are represented as from 1,000 to 40,000 miles long, and from 1,000 to 4,000 miles in breadth. They are frequent near the sun's edge, and often accompany the coming and going of the spots. But they are generally the attendants of the spots, and often appear at points where spots are about to break out. Their bright, concentrated, tortuous appearance in the neighborhood of a spot is represented in Fig. 4.

Another remarkable appearance of the sun's surface consists of

streaks or blades of light—the "slashed straws" of Dawes, or the "willow-leaves" of Nasmyth. These, says Sir John Herschel, cover the whole disk of the sun (except the spaces occupied by the spots) in countless millions, and lie crossing each other in every imaginable direction. Mr. Dawes denies that they are so general, but they are universally recognized in the vicinity of t he solar spots, taking a radial direction around the penumbra, and giving it a jagged or coarsely-thatched appearance. Father Secchi says: "I would compare them to elongated masses of cotton of every possible form, sometimes