Abstract :
C. J. Stahl: Mr. Whitney has spoken of the Joint Committee on street lighting appointed by the New York State Conference of Mayors in cooperation with the Empire State Gas and Electrical Association. Apparently, this committee has felt the desirability of establishing a practical nomenclature in which street-lighting values may be expressed in recognized terms. This idea is commendable and no doubt some progress has already been made. However, we may meet difficulty in using the term lumens per square foot as a measure of illumination if the total lumens output of the lighting unit is to be used instead of the actual lumens applied to the surface of the street. The latter criterion would give the credit due to equipment which utilizes the output of the lamp to better advantage. An upright diffusing ball globe for example, produces practically a uniform distribution in both horizontal and vertical planes with slightly more light above the horizontal than below. Other units employing reflectors or refractors increase the light in the lower hemisphere and distribute it symmetrically over the surrounding area. Still other designs control the light both in the vertical and horizontal planes resulting in still higher illumination on the surface of the street.
