It was not until the time of Emerson and Bryant and Thoreau, however, that our interest in nature became general and grew into something deeper than mere curiosity. There had been naturalists such as Audubon (he was a poet, also), but they went off into the deep woods alone. They were after new facts, new species. Emerson and Bryant and Thoreau went into the woods, too, but not for facts, nor did they go far, and they invited us to go along. We went, because they got no farther than the back-pasture fence. It was not to the woods they took us, but to nature; not a-hunting after new species in the name of science, but for new inspirations, new estimates of life, new health for mind and spirit. But we were slow to get as far even as their back-pasture fence, slow to find nature in the fields and woods. It was fifty years ago that Emerson tried to take us to nature; but fifty years ago, how few there were who could make sense out of his invitation, to say nothing of accepting it! And of Thoreau’s first nature book, “A Week on the Concord and Merrimack Rivers,” there were sold, in four years after publication, two hundred and twenty copies. But two hundred and twenty of such books at work in the mind of the country could leaven, in time, a big lump of it. And they did. The out-of-doors, our attitude toward it, and our literature about it have never been the same since. Even yet, however, it is the few only who respond to Thoreau, Emerson, and Burroughs, who can find nature, as well as birds and trees, who can think and feel as well as wonder and look. Before we can think and feel we must get over our wondering, and we must get entirely used to looking. This we are slowly doing,—slowly, I say, for it is the monstrous, the marvelous, the unreal that most of us still go out into the wilderness for to see,—bears and wolves, foxes, eagles, orioles, salmon, mustangs, porcupines of extraordinary parts and powers.