The conflict arises from the fact that both the telephone and the electric railway use the earth for the return current required for the use of electricity. It does not seem to be certainly known whether the disturbance is due to what is called "leakage," and takes place in the return current in the earth, or whether it is caused by induction between the parallel wires in the air. In either case the current used for the cars is stronger than that used for the telephone, and overcomes it. Whether the disturbance is caused by leakage or induction, there seems to be no doubt that it could be prevented by the use of a parallel return wire by either party; because in this case the induction would be neutralized, and the earth would be used for only one return current. The owners of the telephone say that they have set up their wires by public authority, and are using their instruments in a useful and profitable business, and insist that they should be protected from an interference with their current which will cause them serious damage. They insist that the railways might use a return wire and what is called the double trolley, and ask that they be enjoined from using the earth for their return current. The railways, in reply, ask if the complainants "want the earth" for their exclusive use, and insist that they too can use a return wire, and that by the use of the McCluer device they can do so with less expense than the railroads could do so, and that it is not a case in which the courts should interfere, but that it should be left to the development of electrical science to provide a remedy. The subject has been discussed before boards of aldermen and railroad commissioners, before a committee of the Senate of the United States, and before the courts; a great deal of testimony has been taken, and many arguments have been made. I can only allude to a few of the decisions of the courts.
In Central Union Telephone Co. v. The Sprague Electric R'y, etc., Co., Court of Common Pleas, Summit Co., Ohio, it was held that since it was uncertain whether the railway could use a return wire, and appeared to be probable that the telephone company might obtain relief in that way, the cost of this device would be their measure of damages, and an injunction would be refused. A similar decision was made in June, 1889, in the Chancery Court of Hamilton Co., Tennessee, and a bond in the sum of $10,000 was required of the defendant to secure the payment of the damages.
