The year 1907 must ever be memorable in the history of the development of electric traction, because of the notable installations which have been made on three of the leading railroad systems of the United States. Early in the year we recorded the opening for regular service of the terminal line of the New York Central and Hudson River Railroad Company in this city. Six months later, the New Haven system put in partial' operation the single-phase system on its four-track road from Wood-lawn to Stamford; and in the middle of June, of the same summer, an important change from steam to electric traction was made on a 34-mile stretch of the Rochester division of the Erie Railroad. The same month, also, saw the inauguration of electric operation on forty-four miles of the West Shore steam railroad between Utica and Syracuse, the system used being the direct-current with the third rail, and the equipment being in general similar to that of the New York Central terminal lines, with the important exception that the multiple unit system is used throughout. The equipment of the New York Central and West Shore lines, as well as that of the New Haven system, have already been .fully described in this journal. The Erie electrification is of the same general character as iliat of the New Haven road. A working pressure of 11,000 volts is used on the trolley line, the .current being transmitted at the high pressure of 60,000 volts. The overhead construction is much simpler than that employed on the four tracks of the New Haven road. In the latter case, it will be remembered, each line is made up of two messenger wires with a trolley wire suspended below and between them, by means of rigid triangles. The messenger or suspending wire is of seven strands, and 7/16 of an inch in diameter, and is made of "extra high strength steel." The trolley wire is suspended from this at 10-foot intervals by means- of a series of o/s-inch iron hanger rods. This wire is, of course, much more flexible than that in use on the New Haven system ; and for that reason we should expect to see fewer disarrangements than are liable to occur where the trolley wires are stretched under high tension, and because of the rigid connection of the latter to the triangles are liable to rather serious hammer blows from the contact shoe. The current is taken from the trolley wire by means of pantograph trolleys, and passes through transformers of 200-kilowatt capacity, before it is led to the four 100-horse-power, single-phase railway motors with which the cars are equipped: The control system is of the electro-pneumatic type of thlJ Westinghoue Company, by whom the whole of this work has been done. The above-described equipments serve to operate single cars, with one stop per mile over the entire road, at an average schedule speed of twenty-four miles per hour; or to haul one trailer, making stops about 2% miles apart, at the same speed.