Burroughs's nature essays, charming as they are and full as they are of a delightful personality, will be superseded by others as careful and as charming; Burroughs's criticism was the voice of an era, and it will stand with the era. It was in his later years that he put forth his real message. IV John Burroughs is the historian of a small area; he has the home instinct, the hereditary farmer's love for his own fields and woods, and the haunts of his childhood. He is contemplative, tranquil, unassertive. John Muir was restless, fervid, Scotch by temperament as by birth, the very opposite of Burroughs. He was telescopic, not microscopic; his units were glaciers and Yosemites, Sierras and Gardens of the Gods. The childhood of Muir was broken at eleven by the migration of his family from their native Scotland to the wilderness of Wisconsin, near the Fox River. After a boyhood in what literally was a new world to him, he started on his wanderings. By accident he found himself in the University of Wisconsin, where he studied for four years, the first author of note to be connected with the new state college movement, the democratizing of education. He pursued no regular course, but devoted himself to chemistry, botany, and other natural sciences that interested him, and then, to quote his own words, "wandered away on a glorious botanical and geological excursion, which has lasted nearly fifty years and is not yet completed, always happy and free, poor and rich, without thought of a diploma, of making a name, urged on and on through endless, inspiring, Godful beauty." First he went to Florida, walking all the way, and sleeping on the ground wherever night overtook him; then he crossed to Cuba, with visions of South America and the Amazon beyond; but malarial fever, caused by sleeping on swampy ground, turned him away from the tropics toward California, where he arrived in 1868. The tremendous scenery of this west coast, those American Alps edging a continent from the Sierras to the Alaskan glaciers, so gripped his imagination and held him that he forgot everything save to look and wonder and worship. For years he explored the region, living months at a time in the forests of the Yosemite, in the wild Alpine gardens and glacial meadows of the Sierra, in passes and cañons, moving as far north as Alaska, where he was the first to see the great glacier now called by his name, sleeping where night overtook him, disdaining blanket or shelter, and returning to civilization only when driven by necessity. After years of such wandering he became as familiar with the mighty region, the tremendous western wall of a continent, as Thoreau was with Concord or Burroughs was with the banks of the Pepacton.