BS>Various types of wood, steel, and aluminum window construction, glazed with plastic and different kinds of glass, were installed on four sides of a test structure during the greenhouse tests in order to determine their relative resistance to an atomic blast. The degree of protection from flying glass provided by mounting Venetian blinds, insect screens, and 1/4-in. mesh wire netting on the inside of window openings was also determined. The best results seem to indicate that the resistances of different types of glass to an atomic blast are approximately proportional to their strength in supporting static loads. Glass mounted in a rigid frame is less likely to be broken than if mounted in a flexible frame which may be distorted by the blast. Fragments from wire or safety glass are less dangerous to personnel than fragments from other types of glass, and plastic is less likely to break than glass, Commercial types of Venetian blinds and insect screens afforded littie or no protection against flying glass fragments at the distance at which tested; however, a blind with some of the parts reinforced and properly anchored to the window opening would. probably give some protection at a distance of 3 miles …