independent three phase lines to be used. This allowed for repairs, maintenance and new installations without shutting the whole system down. The poles were planted about apart to string the power lines. Telephone lines were run beneath the power lines. Once in Sacramento the high voltage power was shipped near where it was going to be used and transformed down to a lower voltage for use—the same as electrical power is shipped and used today. By 1895 almost 900 electric street railways and nearly 11,000 miles (18,000 km) of track had been built in the United States and they were then one of the main users of electrical energy. Direct current electric motors, as used on electrical streetcars, were restricted in use to being only a few miles from the DC generators. DC power, despite its restrictions, had become very useful. A rotary converter, a type of motor generator, was used to convert alternating current (AC) to direct current (DC) for railway electrification from an AC power source. Factories were also heavy power users. Transforming AC voltages up to high voltages for long-distance transmission and down to lower voltages at locations close to their use was a very attractive way to get access to a new source of power. Improvements in transformer design allowed the original air cooled transformers at the Folsom powerhouse to be replaced in 1900 with more efficient oil cooled transformers. The alternating current electric induction motor was independently introduced in 1888 by Galileo Ferraris and Nikola Tesla, by 1895 was beginning to allow electrical power to replace steam as a power source. The induction motor allowed alternating current to be used directly without any conversions. The first heavy AC motor users were various factories which typically replaced their steam power plants. Alternating current electrical power and its easy conversion with transformers from low to high voltage and back to low voltage made possible the widespread electrical grids we routinely use today for a myriad of tasks. On September 9, 1895, the new power provided by the powerhouse was celebrated in a "Grand Electric Carnival" decorating the Sacramento state capital with thousands of light bulbs to celebrate the 45th anniversary of California statehood. Lower powerhouse A second powerhouse was constructed below the original facility in 1897 to house an additional 750-kilowatt AC generator to meet the growing residential and public transit electricity demands of Sacramento. This generator