EARTH-SHINE, the reflection from the moon of the light cast upon her by the earth, particularly noticeable in clear nights at the time of new moon, when sometimes the whole surface of the moon can be seen in ashy colored light. The earth serves the same purpose to the moon that the moon does to the earth; that is, the earth is the moon's moon, and would present to an observer on the moon the same phases that the moon does to us: but the earth would, to an observer from the moon, appear four times as large as the moon does to us. When it is new moon to us, it is full moon to an observer on the side of the moon facing the earth, and, as the earth is much the larger, it gives to the moon about 16 times as much light as the full moon gives to us. This light, reflected back to us, is known as earth-shine. It is really the light of the sun reflected by the earth to the moon, and by the moon back to the earth.
in fortification, is a general name for all military constructions, whether for attack or defense, in which the material employed is chiefly earth. The word earthwork, however, has lately received a new importance, in reference to a dis cussion among military engineers, whether earthwork defenses generally are better or worse than those of masonry. The subject cannot be discussed here, but its general character may be indicated. The fracture of the Russian granite fortifications at Bomar
sund, and the obstinate defense made within the earthen defenses at Sebastopol, led many writers, about the year 1855, to express a preference for earthworks instead of stoneworks. Mr. J. Fergusson (Portsmouth, Protected, 1856) has especially distinguished himself by his advocacy of this view. The reasons urged are—that masses of earth can be more quickly and cheaply put up than masses of masonry; that in most places earth is more readily obtained than stone; that if an earthwork be knocked to ruin by balls and shells, it can be repaired in a very short time; and that the defenderi are not exposed to so much injury as in masonry-works, where splinters of stone fly about iu a perilous The late sir John Burgoyne, the leading military engineer in England of his day, combated these views. He contended, among other things, that as a given amount of cannonading will make a much larger breach in earthwork than in stone work, the latter is best fitted to prevent capture by assault. He insisted that earthworks should be regarded rather as temporary expedients than as purposed and permanent constructions; and he claimed the authority of continental engineers in support of this opinion. See further under FORTIFICATION.