. Electrical news and engineering. , / •V / >, — L. ■^ ^ ~ X-- «= ~ ■N, »^ \. ^ ^ e< ^ YT ■—- ^^ ^ ^ - ^ ~., ^ - ^ ^ — ^ = ^ -= i^ - = a ^j- E = ^ ^O 1— ?0 ■■ 3 0 — ■f 0 S 0 8—Curves showing difference in road illumination from one automo-bile head lamp equipped with different types of glasses road illumination from each lamp for the different glassesinvestigated. The curves serve as a check on the distributioncurves, Fig. 8. So far we have considered photometry in the is another very different branch that takes us out intostreets, stores, offices, factories and anywhere
. Electrical news and engineering. , / •V / >, — L. ■^ ^ ~ X-- «= ~ ■N, »^ \. ^ ^ e< ^ YT ■—- ^^ ^ ^ - ^ ~., ^ - ^ ^ — ^ = ^ -= i^ - = a ^j- E = ^ ^O 1— ?0 ■■ 3 0 — ■f 0 S 0 8—Curves showing difference in road illumination from one automo-bile head lamp equipped with different types of glasses road illumination from each lamp for the different glassesinvestigated. The curves serve as a check on the distributioncurves, Fig. 8. So far we have considered photometry in the is another very different branch that takes us out intostreets, stores, offices, factories and anywhere where illumin-ation is to be measured. Of course work of this kind must be done with portablephotometers. These photometers are usually built for a verywide range of work, such as measurements of c. p. in anydirection, foot-candle and surface brightness. To make asurvey of illumination the area selected should be repre-sentative of the conditions, as regards the surroundings, that. Fig- 9Distribution curves of a gas-filled lamp equipped with a prismatic curves show the effect of different vertical positions of thelamp filament. An example of a case wherf a large number of candle-power measurements must be made to obtain the true distribution curve lieen made on a plane 30 inches above the road. This hasbecome a sort of standardized method with us to enable com-parisons to be made. Sometimes vertical illuminations onan adjacent wall is required and in interiors the brightnessof fixtures and the ceilings against which they are reviewedor the brightness of reflections from polished surfaces. The Electric Club of Toronto The regular Friday noon-day luncheons nf the ElectricClub of Toronto, were resumed Nov. 8 at the Prince George,the speaker being Mr. Alfred T. DeLury, Professor of Mathe-matics in the University of Toronto. Professor DeLuryspoke on the subject, On Keeping Step, enlarging upon thenecessity of co-operation and a co-ord
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