In the dead of winter, 1908, the first open-air school in the United States commenced class in Providence, RI. Housed on the second floor of an old school building in a crowded section of the city, this new school—actually an ungraded class in which the enrollment never exceeded 25 pupils—had several novel features. Perhaps most striking was that the brick wall on the southern side of the room had been removed and replaced with a wall of windows, hinged at the top and capable of being raised against the ceiling by means of cords and pulleys. Except in driving snow or rain, these windows were kept wide open. To protect them against the cold, the children (age range, 6 to 13 years) who were chosen for this class because they were sickly, anemic, undernourished, or showing early signs of tuberculosis and because, owing to their ill health, they had failed