Franklin (Chicago) summer open air school, 1917, manual training class. Open air schools or schools of the woods were purpose-built educational institutions for children, that were designed to prevent and combat the widespread rise of tuberculosis that occurred in the period leading up to the WWII. The schools were built on the concept that fresh air, good ventilation and exposure to the outside contributed to improved health. The schools were mostly built in areas away from city centers, sometimes in rural locations, to provide a space free from pollution and overcrowding. The creation and design of the schools paralleled that of the tuberculosis sanatoriums, in that hygiene and exposure to fresh air were paramount; open air schools however also provided education. No photographer credited, dated 1917.