. The Street railway journal . eration of this linehas been the remarkable difference betweenthe insulation resistance between conductorand ground of the positive and negative sides■ of the circuit. This varies on the foreach section, as shown by Mr. Connett in theJournal for February, from 6000 to 8000ohms on a wet day to from 25,000 to 36,000ohms on a dry day. The negative conductorunder similar conditions shows an insulationresistance of from 300 to 400 ohms and from700 to 1000 ohms. This leakage cannot be dueto difference in the construction of the circuits,because when the polar
. The Street railway journal . eration of this linehas been the remarkable difference betweenthe insulation resistance between conductorand ground of the positive and negative sides■ of the circuit. This varies on the foreach section, as shown by Mr. Connett in theJournal for February, from 6000 to 8000ohms on a wet day to from 25,000 to 36,000ohms on a dry day. The negative conductorunder similar conditions shows an insulationresistance of from 300 to 400 ohms and from700 to 1000 ohms. This leakage cannot be dueto difference in the construction of the circuits,because when the polarity of the conductorsis reversed, the high insulation remains acharacteristic of the positive and the lower in-sulation of the negative conductor. The realcause has not jet been determined, but it maybe that it can be explained by the theory of adeposition on the negative insulators due toelectrolytic action. The companyhas made a fewslight changes in theconstruction of in-sulators since theirdescription in theStreet Railway. FIG. 2.—METHOD OF ASSEMBLING INSULATORS. Journal. These changes have been of a mechanical na-ture and designed to facilitate adjustments and construc-tion. One of these is a change in the clip, illustratedin Fig. I. This improvement lies in the of atoothed washer which engages with correspondingteeth in the malleable iron clip. Formerly linerswere used to adjust the position of the clip in the con- 300 STREET RAILWAY JOURNAL. [Vol. XII. No. 5. duit, but these are now avoided by the construction shownin the engraving.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
