Electrolytic survey of loop district in Chicago and electrolysis of water mains . rom this^mass ofiron, corroded ty one ampere inone year is .00029 X 60 X 60 X 24X 365 grammes or , 00029 X 60 X60 X 24 X 365 X .002 205 = 20 #. If the electrolyticcurrent were constant in a pipeand it would corrode the entiresurface at the same time, itwould he an easy matter to ascertainwhen the pipe would be destroyed,but this is not the manner inwhich electrolysis occurs. Thecurrent changes invariably, asshovm by the curves. Some ofthis current may be corrodingthe Iron and some may not. Thewater pipe acts as a
Electrolytic survey of loop district in Chicago and electrolysis of water mains . rom this^mass ofiron, corroded ty one ampere inone year is .00029 X 60 X 60 X 24X 365 grammes or , 00029 X 60 X60 X 24 X 365 X .002 205 = 20 #. If the electrolyticcurrent were constant in a pipeand it would corrode the entiresurface at the same time, itwould he an easy matter to ascertainwhen the pipe would be destroyed,but this is not the manner inwhich electrolysis occurs. Thecurrent changes invariably, asshovm by the curves. Some ofthis current may be corrodingthe Iron and some may not. Thewater pipe acts as a conductorjust the same as copper would. Ifa metallc connection were madefrom the track to the pipe at <??? ? ij soma distance from tiie PowerHouse, and aa other connectionmade from the pipe to the railat the Power House, the pipe as a mere Shunt return andthis current flowing would notbe electrolytic. Of course,other currents enter and leavethe pipe at different locationsand it is these currents thatleave the pipe which corrode theiron. EETUEIT ABMOtTB XMMXXTUlB OB JTSCaNOl-OWX LJUtMJLMX, 10 It is now practicallyagreed that tiie reason for theextraordinary corrosion is to befound in the imperfect characterof the retiirn circuit of electricrailways, When such railwaysweie first constructed, therails, in connection with thesurrounding earth, were reliedupon to carry all the currentback to the generator. It wassoon discovered, however, thatthe current would not confineitself to this path and that theresistance of the earth was farfrom being as low as was originallysupposed. Bonding the rails,cross bonding supplementary wiresand ground plates were than last was found to be of avail, while the copperbonds and supplementary wireswere often themselves electrolysedand bond wires had been frequently 11 far too small in cross section for the large current to be is little doubt that witha perfect return system, whichis properly
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Keywords: ., bo, bookcentury1900, bookdecade1900, bookidelectrolyticsurv00bueh
