Page:Popular Science Monthly Volume 19.djvu/242

230 tiny sea was dotted with an archipelago of islands, whose nearing shores, gradually joining, formed chains of islets; how the inclosed area of water contracted, and, in the union of all their separate figures, vanished. The wet surfaces, broken by depressions, were marked by pits of water from whose sides stole along intermediate creases, threadlike lines of water, the river system of the miniature continent, its sinuous shores impressed by the ripples of a mimic sea. The recollection of boyish pleasures becomes touched with a deeper interest when one is taught to recognize in this the picture of what in a larger way, and under cosmic conditions, has happened in the life-history of our own sphere, and to realize that his childish hand may have reproduced at will a somewhat exact copy of the stages of the world's growth.

Suppose this little world so briefly made had been left till the bright sunshine had dried its surface, in some places parched and cracked it, in others evoked a luxuriant growth of grass and flowers, filled its shores with gliding snails and its level mead with teeming ant-hills. Once more the running stream is stopped, and slowly the muddy tide rises higher and higher, obliterates the lowlands and creeps slowly up the sides of the high ground, around the skirts of its pygmy mountain-chains, and rolls restored amid groups of remade islets. Under the guidance of this retrospective knowledge let the current be arrested to permit some portions of that first-made land to remain uncovered. With favorable conditions, as a stream carrying abundance of fine silt, the water moving sluggishly over the inundated surfaces will drop its earthy burden upon them in thin, loose layers, evenly at first, but, as shallows are formed, irregularly modified, or as sudden freshets produce stronger currents, eddies and ripple-bars gather or disturb the sediment. New lands in wet banks and knobs will begin to appear over the highest ridges. Break away again the barrier, and cause the water to recede, exposing in a similar succession of phases the bared surface. The expectant eye now notices certain changes: old landmarks are removed from sight, valleys have been converted into plains, new hills have arisen, lakes are seen here and there where before was dry land, new contour lines surround the structural ridges which yet remain, modified indeed, but distinctly recognizable, while the low verdure of grass and the numerous pinnacles of ant-hills have together disappeared beneath a universal blanket of mud. Only upon the very highest points do the scattered remnants of the first surface appear unchanged, because they alone were exempted from general flood. Again the sun shines upon it, new seeds sprout, other insects flourish, and fresh showers fall. In spots the old land is exposed; the new having been washed away from it; it may be easily recognized by its fauna and flora, the drowned ants, and the hidden grass.

Again and again, under varying conditions, may our experimental