. Electric railway journal . ve utiliza-tion efficiency per cent. To determine the effect of the shape of the ceiling onthe light distribution, a special headlining consisting ofa white enameled insert, having a 3-ft. span on an , was inserted and the test repeated (Fig. 16).This raised the average foot-candles to and atnormal and 85 per cent voltage respectively, effectivelumens per watt to , and the utilization efficiency per cent. The insert was then removed and the test repeatedwith a different spacing of the units. This resulted ina little improvement i
. Electric railway journal . ve utiliza-tion efficiency per cent. To determine the effect of the shape of the ceiling onthe light distribution, a special headlining consisting ofa white enameled insert, having a 3-ft. span on an , was inserted and the test repeated (Fig. 16).This raised the average foot-candles to and atnormal and 85 per cent voltage respectively, effectivelumens per watt to , and the utilization efficiency per cent. The insert was then removed and the test repeatedwith a different spacing of the units. This resulted ina little improvement in distribution. The principaltrouble was that the car headroom was not sufficient toallow the lighting units to be hung the proper distancebelow the ceiling. The next equipment tested required special reflectingdevices. Ten 56-watt clear tungsten lamps were locatedin a single line down the center of the ceiling, with five10-watt all-frosted emergency lamps in rosettes betweenthem. Each 56-watt lamp was equipped with a screen. NEW YORK MUNICIPAL CAR—FIG. 16—SEMI-INDIRECTLIGHTING WITH SPECIAL CEILING INSERTS made from a circular piece of glass bent over a cylinder(Fig. 14). This gave a screen 11 in. long x 8 in. wide x3 in. deep. When these screens were hung beneath thelamps with their open ends toward the side of the car, itwas possible to see the lamp filaments from any part ofthe passenger car body; at the same time the directlight from a considerable portion of the lamp fell on theceiling and reached the reading plane with but one re-flection, making the system fairly efficient. The dis-tribution lengthwise of the car was even, though theoutboard seats received considerably less light than thecenter aisle of the car. The average intensity was foot-candles at normal and 85 per cent voltage,the energy consumption watts per square foot,effective lumens per watt , and effective per cent. The chief advantage of this equipmentwas the ease wit
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