But machinery is not everything in life. Suppose that as you ride along your eye is caught by the great beauty of the flower gardens by the roadside, their blossoms bright in the morning sunshine and sparkling with the yet undried dew, as if sprinkled with diamonds. Perhaps your attention may never before have happened to be called so strongly to these objects, and possibly you have hitherto remained almost unacquainted with the names and peculiarities of some of the most common plants and flowers. But this morning, for some accidental reason, which may have a psychological origin, you are particularly charmed with the brilliant sight, and you resolve that you will be no longer ignorant of what could, manifestly, give you so much pleasure, besides being of unquestionable usefulness. When you return home you will take up the volume on botany, and it may lead you into a realm of mental delight previously unknown to you. If it is the springtime, you may be interested by the sight of a tall, graceful tree, as lofty as a pine, and as straight in trunk, with many exquisite blossoms hanging from the pendulous stems on its great limbs, fifty or more feet above the ground, as if it were a flower garden in the air for the special delectation of the birds. Having never heard of a flowering tree outside the tropics, you feel a keen desire to know what this one is, and thus a way of introduction, founded on keen, personal interest, is opened for you to the science of botany. And few persons can take a ride, or a walk, anywhere in city or country or park, without having attention attracted by some unknown flower or plant, or tree, and without becoming aware how much pleasure is lost, and how much useful knowledge missed, by lack of the easily acquired knowledge of these things, which anybody can have by giving to it only that amount of time which would otherwise be wasted almost as completely as if the eyes were kept closed and the mind dismissed from its home in the brain. More mysterious, and not less fascinating than flowers and trees, are the birds and insects that flit by on their own errands. To explain them you have the volume on zoölogy, the science of animal life. Botany and zoölogy together go far to revolutionize the ordinary man's ideas about the attractiveness of outdoor life.