It probably dates around 1910. These lamps produce and burn acetylene, and were originally used in mines, before they became a more common form of illumination for vehicles and buildings.

100+ Year Old Rusty Joseph Lucas Bicycle Carbide Lamp Restoration ‘We’re Just a Little Hurt’—Canadian, Minnesota Border Towns Wonder if They Are Still BFFs ‘Easily one of the best shows ...

The helmet could carry a regulation bracket for a carbide lamp, and could be ordered in any size. Edward W. Bullard continued to improve his father’s safety hat, patenting several inventions in 1928 ...