HARVARD LAW REVIEW. VOL. IX. MARCH 25, 1896. NO. 8. CONFLICTING RIGHTS OF TELEPHONE LINES AND SINGLE TROLLEY ELECTRIC RAILWAYS IN THE HIGHWAYS. THE electric lines which are ordinarily found in the highways may be divided into three classes: — 1. Wires for the transmission of intelligence by electricity, including telegraphs, telephones, fire alarms, police signals, and a few others of similar use. These wires transmit an electric cur- rent of very slight potential, and are wholly harmless. 2. Wires for the transmission of electric power for the operation of electric railways. These wires are the overhead trolley wires, and transmit a current of about 500 volts, and are considered harmless to human beings so far as permanent ill effects from shocks are concerned, except in case of very weak or nervous people. The current is strong enough, however, to give a serious temporary shock to human beings, and is often fatal to horses. 3. Wires for the transmission of electric light, heat, and power for mechanical purposes. These wires transmit currents of very high potential, which in case of the direct electric light current is generally in the neighborhood of 2,500 to 3,000 volts, and in case of alternating currents is of much greater destructive force. The electric light current is fatal to human life if taken in its full strength. There are occasional conflicts between all these various kinds of wires as to the occupation of the highways, for the stronger current of one kind will, under circumstances of proximity, affect 65
