This primitive central station in Pearl Street was a converted warehouse of brick construction, four stories high, and it was separated in two parts by a fire wall. One of these parts was used for the storing of underground supplies, while the other was occupied by the generating machinery, for the support of which a special foundation of steel and concrete was provided. The necessary steam boilers were accommodated in the basement, while the second floor was occupied by six generators of 125 horse-power each, nicknamed "Jumbos."

Simple as sounds this original Edison equipment, it nevertheless represented years of research and experimenting on the part of Edison and those associated with him.