Prior to the 1920s, miners wore a soft cap made of cloth or canvas with a leather brim and lamp bracket to hold their light. But in 1919, Edward D. Bullard of San Francisco, California developed the ...

Just like the soft mining caps that were used to hold oil-wick or carbide mining lamps, mining helmets were used to hold the new electric cap lamp. The lamp sat in a bracket at the front of the helmet ...