Comparison of indirect and direct illumination . 35 CALCULATED DATA 1 003 %6 Intensity Foot-candles Ft. I j ooss© rt 0 0 01 46 1 7 rt 1 8 47 2 14 41 50 rt rt T 1 3 rt /\ 20 33 53 4 2G 34 56 5 32 0 62 6 3G 54 66 0. 530 7 41 rt t 2 7 1 f\ a rt a o o 45 01 70 n y 48 20 68 1U 51 201 62 11 54 01 59 12 56 201 55 rt *i m /» 0. 146 13 50 25 50 rt ^ T rt 14 60 15 47 rt rt O rt 15 rt *i 61 r r- 1 55: 45 lb 63 30 43
Comparison of indirect and direct illumination . 35 CALCULATED DATA 1 003 %6 Intensity Foot-candles Ft. I j ooss© rt 0 0 01 46 1 7 rt 1 8 47 2 14 41 50 rt rt T 1 3 rt /\ 20 33 53 4 2G 34 56 5 32 0 62 6 3G 54 66 0. 530 7 41 rt t 2 7 1 f\ a rt a o o 45 01 70 n y 48 20 68 1U 51 201 62 11 54 01 59 12 56 201 55 rt *i m /» 0. 146 13 50 25 50 rt ^ T rt 14 60 15 47 rt rt O rt 15 rt *i 61 r r- 1 55: 45 lb 63 30 43 1 olo /-» /-» 66 5 41 20 68 101 39 <d4 71 nrl 35 37 rt rt T O 28 74 5* 36 rt rt T rt 32 76 rt t 0 36 77 301 35 40 78 50 I I t I I. U- Or I. S. *? FORM J 37 DISCUSSION. The illumination on the 2 ft. 6 in. plane was found to be very uni-form for the points taken, the smallest values being obtained near the edgesof the room. For light walls these values might be multiplied by a , but, owing to the great surface that is occupied by the windows and theblackboards, this was not done, the data being considered sufficiently ac-curate. From the data it can be 3een that the installation of this systemwould be advisable, since the uniformity of the distribution of illuminationthroughout the plane considered is very good. The one great fault in thi3 system is that the light will necessarilybe in the line of vision, and the glare of the direct rays is injurious tothe eyes. The table,given on the next page, was obtained from a reliablea source. It gives a firly good idea of the average foot-candles of illuminationrequired for rooms used for various purposes. 33 AVERAGE FOOT-CANDLES riesictsncc living—rooms TX of
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1912
