Follows five inventors: Elijah "the real" McCoy, machinery oiling equipment; Madame C.J. Walker, hair products for black women; Granville Woods, electrical signal system for trains; Garrett Morgan, gas masks and traffic signals; and Jan Matzeliger, shoe last machinery.
內容簡介
Follows five inventors: Elijah "the real" McCoy, machinery oiling equipment; Madame C.J. Walker, hair products for black women; Granville Woods, electrical signal system for trains; Garrett Morgan, gas masks and traffic signals; and Jan Matzeliger, shoe last machinery.
2026專利防護中