. The principles of hygiene; a practical manual for students, physicians, and health-officers . Fig. 8.—Wall air inlet. Fig. -Cowl. Perflation may be aided by means of cowls attachedto the tops of chimneys and ventilating shafts. Theseare composed of two tubes, one within the other,having a hooded cover with one large opening, at rightangles to the mouth of the chimney, which is turnedtoward the point from which the wind is coming anddirects its current downward through one of the may be either movable or fixed; the latter being ARRANGEMENTS IN NA TURAL VENTILA TION. 69 the preferab
. The principles of hygiene; a practical manual for students, physicians, and health-officers . Fig. 8.—Wall air inlet. Fig. -Cowl. Perflation may be aided by means of cowls attachedto the tops of chimneys and ventilating shafts. Theseare composed of two tubes, one within the other,having a hooded cover with one large opening, at rightangles to the mouth of the chimney, which is turnedtoward the point from which the wind is coming anddirects its current downward through one of the may be either movable or fixed; the latter being ARRANGEMENTS IN NA TURAL VENTILA TION. 69 the preferable form, because it is less liable to get out oforder. The best form of cowl consists of a fixed down-cast tube with expanded, trumpet-shaped mouth, abovewhich is a conical cap, the apex of which is turnedupward (Fig. 9). By means of this arrangement the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecthygiene, bookyear1901
