His notebooks show the broad scope of his observations and of his studies. They cover every corner of natural life. One day he would go out and bring back material for pages of memoranda concerning the chase of what he believed to be a hermit thrush. On another day he makes an entry of fourteen varieties of golden-rod analyzed, six kinds of aster, and, as he adds, “many others.” One page of his notes gives the results of careful experiments with three dozen dandelion blossoms, to determine how long the flower requires to pass from bud to the state when it floats away in silvery down. Another passage records in a minute description his first observation of the snapping of the witch-hazel seeds, to which he adds a list of a dozen subjects for illustration. He counts the number of different plants he finds in his city back-yard. He sets down the things seen in a walk through the Park with a lantern, from nine o’clock to eleven at night. He notes that on a certain June 29th, in the midst of a heavy thunder storm he heard the song of the Wilson thrush in the woods near his house. He makes liberal memoranda of the things most touching his attention after a fresh snow-fall. He sets down a list of more than a score of birds whose song he heard “in a continuous roundel,” while sitting on his porch on a quiet Sunday. Thoreau in his hermit haunts at Walden was not more minute and attentive in his observations than this eager three-fold worker, hurrying from city to country and back to city again, equally busy at sketching, and writing, and observing. There are pages upon pages of his notes which read like the “Natural History of Selborne” in their detailed and leisurely narrative of things seen and heard in the fields and beside the brooks. In these records of his intermittent life in the country one never hears the faintest echo of the bustling round of the dweller in cities. He drops all that when he locks the door of his town-house behind him. Once in the open air he is again the free and buoyant youth, preoccupied only by the purposes and the pursuits which belong to the open air, the meadow, and the wood. Indeed it seems as if his early training and experiences, those school-days at the “Gunnery,” the passions there born, the habits there fostered and confirmed, lay at the basis of all his life afield. He himself somewhere said: “To the average observer, if the eye is ever thus to be a means of grace, it must store up its harvest while hearts are light and life is new, when eyes are bright and undimmed. How many a prisoner caged in city walls is living on the harvest stored in free, unburdened youth, which has never been replenished.” Perhaps that was true of this observer so much above the “average,” and caught for half his time in the city’s durance. But even there he proved again the truth of Lovelace’s lines: “Stone walls do not a prison make Nor iron bars a cage.” He made the city rural, and told others his secret: