flow, with a centrifugal governor, to obtain 300 shaft rpm—needed to generate a steady 60 cycle current. Alternators The four alternating current generators are some of the most powerful rotating armature 3-phase machines ever built. Newly invented by Elihu Thomson, they weighed almost 30 tons each (57,887 pounds) and were . These original AC generators used many DC generator components in their first design. The 750-kilowatt (1,005 horsepower) alternating current generators were made in the newly incorporated General Electric plant in Schenectady, New York. The alternators had rotating armatures with 216 radial 4 inch slots formed into the perimeter. Each slot holds two insulated 3 1/2 foot rectangular inductive bars of related phase, an inner circle of 216 bars and an outside circle of 216 bars. The induction bars are twice bent into offsets in the same direction. The middle of the bar has a straight section 3 feet long, to get from the front of the rotor to the back. The inner circle of bars is connected to the outer circle by small conductive jumper blocks on the front and back of the rotor. The rotor's three phases are connected to six branch circuits. Each of the six branch circuits make their way three times progressively around the rotor in right hand flattened spirals. Supplying power for the 24 stator (non-rotating) field coil magnets on the AC generators was a small direct current generator with another DC generator in standby mode for immediate substitution if needed. If one DC generator failed or needed maintenance the other one could be used. All four AC generators power were connected to each other, when long-term demand increased and it was found that tying generators together improved frequency control, by synchronizing action. Switch panel To allow customers to use electric clocks regulated by synchronous motors, a Frequency "Indicator" was added to the Powerhouse switchboard. To allow parallel alternators and power grid, a Synchroscope was added to the Switch Panel. Transmission lines The AC power generated (about 4,020 horse power or 3 MW) at the Folsom hydroelectric facility was converted to 11,000 volts at the power plant by twelve new (in 1895) air cooled transformers invented by William Stanley, Jr. and transmitted to Sacramento on twelve bare #1 AVG copper wires held by ceramic insulators that were attached to the cross beams mounted on two sets of cedar poles. The multiple wires allowed four