Page:Popular Science Monthly Volume 5.djvu/553

Rh Any one, for instance, who has looked down upon the Mediterranean from the summit of Gibraltar or Capri, and can recall its curious unlikeness to its familiar aspect—its apparent stillness, the faint intricate bands of white and gray, which, thus seen, overlap it like a net-work of broad veins, and the strangely permanent patterns left by the foam, which are entirely lost to us as we approach its tossing surface—will have a not wholly inadequate idea of the first impression made by the sight of the photosphere. If we bring ourselves nearer, as it were, by an increase of magnifying power, we lose sight of the larger masses of light and shade, whose place is filled by a curious mottling of faint, inextricably confused, and intermingled moss-like patterns.

With the best optical aid, and in those rarer moments when our own atmosphere is comparatively tranquil, we discern that the whole of these cloud-like mottlings are composed of very minute definite oval forms, which have been compared to grains of rice.

Minute as they appear, their real size is very great; for, though in a large telescope they seem mere dots, the average area of each is certainly much over 100,000 square miles. Since we see them at all, it must be owing to some inequality of brightness which distinguishes them, and, in fact, they do not seem to be in absolute contact, but present rather the appearance of numberless little white clouds, arranged with a sort of order upon a background of darker sky, or, if we compare them to rice-grains, we may suppose the grains arranged in rude tesselated patterns upon a gray cloth.

The most extraordinary conjectures have been hazarded as to the real nature of these objects, which are of somewhat recent discovery, and which are so difficult of observation that few have distinctly seen them. Whatever these things may be, they are the principal source of the sun's light, and presumably of its heat, and this adds to the interest of their study.

The writer has given a considerable time to their observation, which can only be carried on successfully by patient waiting, and the employment of those scattered moments when the ever-perturbed atmosphere of the earth is relatively still. He has been led to conclude that these bodies are composed of still smaller forms, and that their total area is inconsiderable compared with that of the whole sun, for, though it is almost impossible to determine the aggregate space occupied by such minute things, the writer has been led to conclude that it can hardly exceed one-fifth of the solar surface, and may be much less. An inconsiderable part only of the solar light comes from the relatively dark background on which they appear, and, in reference to these still mysterious things, we may, then, partly adopt an expression which Huyghens used with regard to the faculæ, and say that there is indeed in the sun "something brighter than the sun itself." The expression will not appear a forced or exaggerated one if we reflect