The engineer of the Chicago Commission on Ventilation, W. J. Mauer,1 has remarked that the ventilating engineer stands in ill repute today in the eyes of many, not because of lack of knowledge or skill on his part, but because of lack of uniformity of opinion and the need of standards of good air conditions and installation methods. Ventilation is a definite problem which cannot be solved by the haphazard method of opening a window here and there. When one stops to remember that mankind is more immediately dependent on air than on either food or water, it seems surprising indeed that so little serious attention and scientific study have been devoted to the air we breathe, in comparison with diet and drinking supplies.
Motion, coolness, a certain degree of humidity, freshness—each of these factors has at some time been emphasized in relation to proper ventilation. The fear of