For many years nearly every waking moment was spent in doing some kind of manual work. However, he was hungry for knowledge, and eagerly read the few books which came his way. Among these were the Bible, parts of Shakespeare's poems, and selections from Milton, Cowper and others, not often read by boys of his age. When he was twenty-three he decided to attend the State University. His father told him that he would have to support himself by his own efforts. This he did, first by living very simply, and then by seizing every opportunity to earn a dollar. He taught school and worked in the harvest fields during the long summer vacations. When in college he lived so frugally that sometimes he did not spend more than half a dollar a week. The greatest interest of John Muir's life had always been the things he found in nature. From the days when, as a little fellow, he played around the fields and streams near Dunbar in Scotland, he had loved the open air and the hundreds of things which lived and grew there. When he did finish his course at college he suffered from eye trouble, and was even threatened with blindness. He there and then decided to live in the open and see as much of the world as possible. He set out on a walking tour through several States. He visited Cuba, then the Isthmus of Panama, and then went straight to San Francisco, where he arrived with less than a dollar in his pocket. This distance was all covered on foot. He slept in the open most of the time and gathered biological specimens as he went. Sometimes he ran completely out of money, and when this happened he secured work until he had sufficient to proceed. Soon after he arrived in San Francisco he visited the Sierra Nevada Mountains, and from then until the time of his death he found these great hills a source of never-ending joy. He tramped among them until he knew them thoroughly. It was chiefly through his efforts that Congress set aside Yosemite as a national park. He was often called "Father of the Yosemite." In 1876 he was appointed a member of the United States Coast and Geodetic Survey, and he saw Alaska, where he travelled hundreds of miles alone. Later he visited Siberia, Norway, and Switzerland. He did not hurry through those lands as many tourists do, but wherever he went he studied, with much care, the flowers and the animals that lived in the great open spaces. Things which others passed with only a glance he closely observed. His passion to study these things led him to visit India, Russia, Australia, New Zealand, Brazil and many other countries. He travelled thousands of miles on foot and generally slept in camps and tents.