These headlamps are typical of the lights used underground. Although this lamp has an outdated look, current underground models are similar in shape and size. Technology has improved the brightness of the lamp, the safety, and longevity of the battery.
Historically, the most primitive method to light a mine shaft was simply when candles in metal holders were spiked into the rock wall. At that time a type of head lamp was used when a candle holder was hooked in front of the miners felt hat. The wide brim prevented wax from dripping on the miners face. By 1915, carbide lamps were used underground. These early headlamps produced light from a carbide reaction. Water was dripped onto carbide crystals, which produced a gas that burned with a bright flame. These lamps were not terribly safe and the electrical headlamp became more commonly used by the 1920s. It was after the First World War that miners began wearing hard hats. Men returning from the trenches of the Great War appreciated the importance of head protection. They quickly petitioned the mines to provide them with headgear from the falling rocks.
Electrical lamps were safe and accessible. Since the miners depended on their lamp, they took extra care of their electrical guy, often inviting him out for a beer at the bar at the end of the day. The lamp guy's favourite miners often received the brightest lamps available. Bright lamps were important because the working areas were usually lit only by one's headlamp. A fully charged lamp would last 8 to 10 hours, the length of a shift.
Keno City Mining Museum, Keno City