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A Comprehensive View

earth j and the rays CE, DE, terminatethe earth’s shadow.

The light between F f, and A B, is re-fracted by the atmosphere, and diffused be-tween C E, and A B, and continued beyondE, the point of the earth’s shadow : whenceit is plain, that the light proceeding fromthe fun becomes continually weaker, thefarther it is from the earth; so that theshadow of the atmosphere is but a weaklight, and therefore the moon is visiblein an eclipse.

The shadow of the atmosphere is coni-cal, because the diameter of the sun is greaterthan that of the earth. This cone does notreach so far as the planet Mars: but thediameter of the shadow, in the place whereit cuts the moon’s orbit, is not ith less thanthe earth’s diameter.

A solar eclipse happens, when the NewMoon is in or near the node. In fig. 22.S represents the fun, M the moon, hershadow falling upon DC, a part of theearth’s circumference, which is surroundedby a penumbra. Beyond A and F, theearth is illuminated by an entire hemisphere

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