Читать книгу Star-land: Being Talks With Young People About the Wonders of the Heavens онлайн

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No means of estimating the sun’s size are available when his orb stands high in the heavens. But when he is rising or setting, we see that he passes behind trees or mountains, so that there are intervening objects with which we can compare him; then we have actual proof that the sun must be a very large body indeed.

Fig.10.—A Sunset viewed from Marseilles (Marcus Codde).

I give here a picture, by Marcus Codde, taken from a French journal, l’Astronomie, which gives a charming illustration of a sunset at Marseilles (Fig.10). If you wish to see that the sun is bigger than a mountain, you may go to the top of Notre Dame de la Garde, but you must choose either the 10th of February or the 31st of October for your visit, because it is only on the evenings of those days that the sun sets in the right position.

On both these evenings the sun sinks directly behind Mount Carigou in the Pyrenees; this mountain is a long way from Marseilles—no less, indeed, than one hundred and fifty-eight miles. But the mountain is so lofty, that when the sky is clear, the summit can be distinctly seen upon the sun as a background, in the way shown in the picture. This must be a very pretty sight, and it teaches us an important lesson. The sun is further away than the mountain, and yet you see the sun on both sides of the mountain, and above it. Here, then, we learn without any calculations, that the sun must be bigger than the upper part of a great mountain in the Pyrenees.