At length we come to feel that the Greeks were not far wrong in thinking each tree had a Dryad in it, animating it, protecting it against destruction, dying when the tree withered. Some Faraday shows us that each drop of water is a sheath for electric forces sufficient to charge 800,000 Leyden jars, or drive an engine from Liverpool to London. Some Sir William Thomson tells us how hydrogen gas will chew up a large iron spike as a child's molars will chew off the end of a stick of candy. Thus each new book opens up some new and hitherto unexplored realm of nature. Thus books fulfill for us the legend of the wondrous glass that showed its owner all things distant and all things hidden. Through books our world becomes as "a bud from the bower of God's beauty; the sun as a spark from the light of His wisdom; the sky as a bubble on the sea of His Power." Therefore Mrs. Browning's words, "No child can be called fatherless who has God and his mother; no youth can be called friendless who has God and the companionship of good books." Books also advantage us in that they exhibit the unity of progress, the solidarity of the race, and the continuity of history. Authors lead us back along the pathway of law, of liberty or religion, and set us down in front of the great man in whose brain the principle had its rise. As the discoverer leads us from the mouth of the Nile back to the headwaters of Nyanza, so books exhibit great ideas and institutions, as they move forward, ever widening and deepening, like some Nile feeding many civilizations. For all the reforms of to-day go back to some reform of yesterday. Man's art goes back to Athens and Thebes. Man's laws go back to Blackstone and Justinian. Man's reapers and plows go back to the savage scratching the ground with his forked stick, drawn by the wild bullock. The heroes of liberty march forward in a solid column. Lincoln grasps the hand of Washington. Washington received his weapons at the hands of Hampden and Cromwell. The great Puritans lock hands with Luther and Savonarola.