'The 1st electric version had only red & green lights & had to be worked by hand'
Stop Light/Traffic Signal
INVENTIONS: The 1st electric version had only red & green lights & had to be worked by hand
The 1st electric version had only red & green lights & had to be worked by hand
The 1st electric version had only red & green lights & had to be worked by hand
INVENTIONS
Stop Light/Traffic Signal
INVENTIONS