Among these New Englanders one stands preeminent to our view--Henry D. Thoreau, whom Channing so happily called the poet-naturalist. In him the observation of Nature took the foremost place as a life-pursuit; but it reflected more than the science of Nature alone, though that was there, too, as it must be to make any out-door book of real and living interest. Let some, if they choose, belittle "solid information," and extol "insight"; nevertheless the inner meaning, the imaginative perception of the value of a fact, cannot be expressed in any useful way unless the fact itself is truly and accurately stated and understood, and a reader who trusts altogether to a literary or artistic presentation of out-door life is likely to get some very distorted notions. [Illustration: Photograph by George R. King JOHN MUIR AND A PINE TREE FRIEND] Thoreau's books stand at the foundation of what we now call American out-door literature. It is probable that anybody who reads a single one will be eager to read the others, but this might not happen if he began, for instance, with the "Week on the Concord and Merrimack Rivers." With "Walden" as an introduction to Thoreau, you get the man really in place, for this is the story of his camp life on the shore of Walden Pond, and has the least of those eccentric meditations which elsewhere sometimes puzzle, if they do not bore, the ordinary reader. "Excursions" is somewhat more discursive but equally delightful. "I wish to speak a word for Nature, for absolute freedom and wildness, as contrasted with a freedom and culture merely civil," he declares; and these essays are memoranda of the author's wonderful walks--_wonder-full_ they were. "It was a pleasure and a privilege," wrote Emerson, "to talk with him. He knew the country like a fox or bird, and passed through it freely by paths of his own." [Illustration: Copyright by Underwood & Underwood, N.Y. JOHN MUIR AND JOHN BURROUGHS Called "John o' Mountains" and "John o' Birds" by their friends] Thoreau died in 1862, having published only two books, the "Week" (1849) and "Walden" (1854). After his death there were printed no less than ten volumes prepared from his great accumulation of essays in manuscript, and notes and diaries. The four entitled "Spring," "Summer," "Autumn," and "Winter" are mines of treasure to the Nature student. They consist of dated paragraphs from Thoreau's voluminous journals, the selections being mainly notes on animals and plants seen about Concord at all seasons of the year, with the queries and musings that occurred to him at the moment. They are books to be owned and referred to by the naturalist rather than to be read for entertainment.