Morning journal and courier., 1894-05-08
RLRCTROLYSIS.

It was discovered some time ago that the electric currents -uss3 E the oYsss.te- os street railroads were having a destructive action on the gas and water pipes which run through the strests, and since that discovery electricians have been busy de vising ways to prevent such action. And, wonderful men that they are, they seem to have succeeded. In England the matter has received more attention than in this country, and rules have been adopted by the Board of Trade which electric railroad companies must follow and which are said to be effective for the protection of gas and water pipes exposed to the re- turn current. These rules provide that one of the two conductors must be insulated from earth, but the other need not beinsu lated If formed by the rails, provided 1t is laid within three feet of the rails or is of such sectional area as will reduce the difference of potential between the ends of the uninsulsted part of the return below 8 certain defined limit. Uninsulated returns laid with In three feet of the rails must be con- nected to them at distances not exceeding 100 feet spart by strips of copper not less than a sixteenth of an inch in sec tionsl area, and an uninsulated return must be connected to the negative terminal of the generator, this terminal also to be con- neoted through current indicator to two separate earth connections twenty yards apart, or to @ water pipe of not less than three inches internal diameter. The earth connections must be such that an electro motive force of four volts shall produce current of at least two amperes from one to the other through the earth. An uninsu. lated return must be 80 laid and main tained that the current passing from the earth connections through the in- dicator to the generator shall not at any time exceed. either two amperes per mile of single tramway line or five per cent. of the total current out put of the station; that if 8 current in- dicator is placed between the uninsu- lated return and any pipe in the vi. cinity 1t shall always be possible to reverse the direction of the current by three Leclanche cells in series If the direction of the current is from the return to the pipe, and by one cell If the direction is from the pipe to the return. A, record must be kept of the difference of potential between the parts of the unipsu lated return farthest from and nearest te the generating station-this difference mol to exceed seven volts. The insulation oi all insulated conductors and feeders musi be such that the leakage current does moi exceed one huudredth ampere per mile ol tramway. Insulated conductors laid be low ground must have an iEsula tion resistance of ten megohms pc, mile ct least. When induction is caused on conductors erected previ
 ously, the owners of such wires car apply for permission to insert one or more induction coils in the tramwsy conductors to prevent the disturbance. When the line or the return, or both, are laid in the con. duit, the conduit, If metal, shall afford metallic continuity through its whole length, and when the rails form the return It shall be connected to them, and whe1 the conduit is of non- -metallic material and not of high insulating quality 1t is to b. divided by insulating screens from pipst laid within distance of six feet.
 Those who have not kept track of whA, has been going on overhead and under ground, and in the minds of the electri
 clans will realize after reading the above that there are things which they don, know much about.