Incandescent electric lights . convey the cur-rent to a given number of high-resistancelamps a given distance, than it will to con-vey the current to the same number of lowresistance lamps the sante distance. ECONOMY OF THE LAMPS. The economy of the lamps is deter-mined by the energy consumed and theamount of light produced; in determiningthe energy consumed in the lamps, theelectro-motive force was measured betweenthe terminals of the lamps, and also the re-sistance, and the energy determined in foot e2pounds per minute by the formula^- In measuring the electro-motive force thesame arr
Incandescent electric lights . convey the cur-rent to a given number of high-resistancelamps a given distance, than it will to con-vey the current to the same number of lowresistance lamps the sante distance. ECONOMY OF THE LAMPS. The economy of the lamps is deter-mined by the energy consumed and theamount of light produced; in determiningthe energy consumed in the lamps, theelectro-motive force was measured betweenthe terminals of the lamps, and also the re-sistance, and the energy determined in foot e2pounds per minute by the formula^- In measuring the electro-motive force thesame arrangements were used as in de-termining the electro-motive force of thegenerator, but the damping magnet wasadjusted to give three units of deflectionto a volt instead of five. To measure theresistance of the lamps when burning, thecurrent was divided into two parts, onepart was passed through the lamp and theother through a variable resistance, when ^ 90° 90° CURVE SHOWING ILLUMINATION OF EDISONS LAMP IN A HORIZONTAL CCRVE SHOWING ILLUMINATION OF EDISONS LAMP IN A HORIZONTAL PLANE. 73 both were passed through a differentialgalvanometer, but in opposite directions;when the current was the same in bothbranches, the needle of the galvanometerwould indicate zero. As the electro-motiveforces of the two branches were equal,their currents were equal, when _ theirresistances were equal, so by alteringthe variable resistance until the needlecame to zero, and measuring the variableresistance we thus determined the resist-ance of the lamp while it was variable resistance was measured eachtime before it cooled. As the light given out in a horizontalplane varies at different angles, the angleof average iUumination. was first deter-mined for the ^mp used, which was theEdison lamp. To determine this angle,the candle po^ r was measured every 10°through a quar t, and the candle powerobserved laid o^ on a suitable scale onlines radiated from a point. A curve wasdrawn thro
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Keywords: ., bookcentury1800, bookdecade1880, bookidincandescent, bookyear1882
