He taught school with his brother and lectured, but in order to add to his slender income also did work unusual for a Harvard graduate, such as odd jobs of carpentering, planting trees, and surveying. He also assisted his father in his business of pencil making, and together they made the best pencils in New England. Whatever he undertook, he did thoroughly. He had no tolerance for the shoddy or for compromises. Exact workmanship was part of his religion. "Drive a nail home," he writes in _Walden_, "and clinch it so faithfully that you can wake up in the night and think of your work with satisfaction." Like so many of the transcendentalists, Thoreau desired to surround his life with a "wide margin of leisure" in order that he might live in his higher faculties and not be continuously dwarfed with the mere drudgery of earning his sustenance. He determined to divest himself of as many of the burdens of civilization as possible, to lead the simple life, and to waste the least possible time in the making of mere money. The leisure thus secured, he spent in studying birds, plants, trees, fish, and other objects of nature, in jotting down a record of his experiences, and in writing books. [Illustration: SITE OF THOREAU'S HUT, WALDEN POND] Since he did not marry and incur responsibilities for others, he was free to choose his own manner of life. His regular habit was to reserve half of every day for walking in the woods; but for two years and two months he lived alone in the forest, in a small house that he himself built upon a piece of Emerson's property beside Walden Pond, about a mile south of Concord. Thoreau found that he could earn enough in six weeks to support himself in this simple way for the rest of the year. He thus acquired the leisure to write books that are each year read with increasing interest. The record of his life at Walden forms the basis for his best known work. A few people practice the return to nature for a short time, but Thoreau spent his available life with nature. He was a pronounced individualist, carrying out Emerson's doctrine by becoming independent of others' opinions. What he thought right, he said or did. He disapproved, for example, of slavery, and consequently refused to pay his poll tax to a government that upheld slavery. When he was imprisoned because of non-payment, Emerson visited him and asked, "Why are you here, Henry?" Thoreau merely replied, "Why are you _not_ here?"