Mezue ahịrịokwu na-esonụ: Hammer chịkọtara bọlbụ ọkụ ọkụ sitere n'akụkụ ụwa niile nke akpọrọ "The History of an Art" ma gosipụta ya n'oge dị iche iche na ngosipụta ọkụ eletrik na ihe ngosi. O gosipụtara ya na nke mbụ ya n'afọ 1882 na International Electrical Exposition dị na Crystal Palace dị na London, e nyekwara ya ihe nrite ọlaọcha maka ihe ngosi ahụ. Mgbe o gosipụtara nchịkọta ya na
St. Louis World's Fair nke 1904 e nyere ya nnukwu onyinye.